4 # "Mike had an infinite amount to do and a negative amount of time in which
5 # to do it." - Before and After
8 # The following hash values are used:
9 # value: unsigned int with actual value (as a Math::BigInt::Calc or similiar)
10 # sign : +,-,NaN,+inf,-inf
13 # _f : flags, used by MBF to flag parts of a float as untouchable
15 # Remember not to take shortcuts ala $xs = $x->{value}; $CALC->foo($xs); since
16 # underlying lib might change the reference!
18 my $class = "Math::BigInt";
24 @EXPORT_OK = qw(objectify bgcd blcm);
26 # _trap_inf and _trap_nan are internal and should never be accessed from the
28 use vars qw/$round_mode $accuracy $precision $div_scale $rnd_mode
29 $upgrade $downgrade $_trap_nan $_trap_inf/;
32 # Inside overload, the first arg is always an object. If the original code had
33 # it reversed (like $x = 2 * $y), then the third paramater is true.
34 # In some cases (like add, $x = $x + 2 is the same as $x = 2 + $x) this makes
35 # no difference, but in some cases it does.
37 # For overloaded ops with only one argument we simple use $_[0]->copy() to
38 # preserve the argument.
40 # Thus inheritance of overload operators becomes possible and transparent for
41 # our subclasses without the need to repeat the entire overload section there.
44 '=' => sub { $_[0]->copy(); },
46 # some shortcuts for speed (assumes that reversed order of arguments is routed
47 # to normal '+' and we thus can always modify first arg. If this is changed,
48 # this breaks and must be adjusted.)
49 '+=' => sub { $_[0]->badd($_[1]); },
50 '-=' => sub { $_[0]->bsub($_[1]); },
51 '*=' => sub { $_[0]->bmul($_[1]); },
52 '/=' => sub { scalar $_[0]->bdiv($_[1]); },
53 '%=' => sub { $_[0]->bmod($_[1]); },
54 '^=' => sub { $_[0]->bxor($_[1]); },
55 '&=' => sub { $_[0]->band($_[1]); },
56 '|=' => sub { $_[0]->bior($_[1]); },
58 '**=' => sub { $_[0]->bpow($_[1]); },
59 '<<=' => sub { $_[0]->blsft($_[1]); },
60 '>>=' => sub { $_[0]->brsft($_[1]); },
62 # not supported by Perl yet
63 '..' => \&_pointpoint,
65 '<=>' => sub { my $rc = $_[2] ?
66 ref($_[0])->bcmp($_[1],$_[0]) :
68 $rc = 1 unless defined $rc;
71 # we need '>=' to get things like "1 >= NaN" right:
72 '>=' => sub { my $rc = $_[2] ?
73 ref($_[0])->bcmp($_[1],$_[0]) :
75 # if there was a NaN involved, return false
76 return '' unless defined $rc;
81 "$_[1]" cmp $_[0]->bstr() :
82 $_[0]->bstr() cmp "$_[1]" },
84 # make cos()/sin()/exp() "work" with BigInt's or subclasses
85 'cos' => sub { cos($_[0]->numify()) },
86 'sin' => sub { sin($_[0]->numify()) },
87 'exp' => sub { exp($_[0]->numify()) },
88 'atan2' => sub { $_[2] ?
89 atan2($_[1],$_[0]->numify()) :
90 atan2($_[0]->numify(),$_[1]) },
92 # are not yet overloadable
93 #'hex' => sub { print "hex"; $_[0]; },
94 #'oct' => sub { print "oct"; $_[0]; },
96 # log(N) is log(N, e), where e is Euler's number
97 'log' => sub { $_[0]->copy()->blog($_[1], undef); },
98 'int' => sub { $_[0]->copy(); },
99 'neg' => sub { $_[0]->copy()->bneg(); },
100 'abs' => sub { $_[0]->copy()->babs(); },
101 'sqrt' => sub { $_[0]->copy()->bsqrt(); },
102 '~' => sub { $_[0]->copy()->bnot(); },
104 # for subtract it's a bit tricky to not modify b: b-a => -a+b
105 '-' => sub { my $c = $_[0]->copy; $_[2] ?
106 $c->bneg()->badd( $_[1]) :
108 '+' => sub { $_[0]->copy()->badd($_[1]); },
109 '*' => sub { $_[0]->copy()->bmul($_[1]); },
112 $_[2] ? ref($_[0])->new($_[1])->bdiv($_[0]) : $_[0]->copy->bdiv($_[1]);
115 $_[2] ? ref($_[0])->new($_[1])->bmod($_[0]) : $_[0]->copy->bmod($_[1]);
118 $_[2] ? ref($_[0])->new($_[1])->bpow($_[0]) : $_[0]->copy->bpow($_[1]);
121 $_[2] ? ref($_[0])->new($_[1])->blsft($_[0]) : $_[0]->copy->blsft($_[1]);
124 $_[2] ? ref($_[0])->new($_[1])->brsft($_[0]) : $_[0]->copy->brsft($_[1]);
127 $_[2] ? ref($_[0])->new($_[1])->band($_[0]) : $_[0]->copy->band($_[1]);
130 $_[2] ? ref($_[0])->new($_[1])->bior($_[0]) : $_[0]->copy->bior($_[1]);
133 $_[2] ? ref($_[0])->new($_[1])->bxor($_[0]) : $_[0]->copy->bxor($_[1]);
136 # can modify arg of ++ and --, so avoid a copy() for speed, but don't
137 # use $_[0]->bone(), it would modify $_[0] to be 1!
138 '++' => sub { $_[0]->binc() },
139 '--' => sub { $_[0]->bdec() },
141 # if overloaded, O(1) instead of O(N) and twice as fast for small numbers
143 # this kludge is needed for perl prior 5.6.0 since returning 0 here fails :-/
144 # v5.6.1 dumps on this: return !$_[0]->is_zero() || undef; :-(
146 $t = 1 if !$_[0]->is_zero();
150 # the original qw() does not work with the TIESCALAR below, why?
151 # Order of arguments unsignificant
152 '""' => sub { $_[0]->bstr(); },
153 '0+' => sub { $_[0]->numify(); }
156 ##############################################################################
157 # global constants, flags and accessory
159 # These vars are public, but their direct usage is not recommended, use the
160 # accessor methods instead
162 $round_mode = 'even'; # one of 'even', 'odd', '+inf', '-inf', 'zero', 'trunc' or 'common'
167 $upgrade = undef; # default is no upgrade
168 $downgrade = undef; # default is no downgrade
170 # These are internally, and not to be used from the outside at all
172 $_trap_nan = 0; # are NaNs ok? set w/ config()
173 $_trap_inf = 0; # are infs ok? set w/ config()
174 my $nan = 'NaN'; # constants for easier life
176 my $CALC = 'Math::BigInt::FastCalc'; # module to do the low level math
177 # default is FastCalc.pm
178 my $IMPORT = 0; # was import() called yet?
179 # used to make require work
180 my %WARN; # warn only once for low-level libs
181 my %CAN; # cache for $CALC->can(...)
182 my %CALLBACKS; # callbacks to notify on lib loads
183 my $EMU_LIB = 'Math/BigInt/CalcEmu.pm'; # emulate low-level math
185 ##############################################################################
186 # the old code had $rnd_mode, so we need to support it, too
189 sub TIESCALAR { my ($class) = @_; bless \$round_mode, $class; }
190 sub FETCH { return $round_mode; }
191 sub STORE { $rnd_mode = $_[0]->round_mode($_[1]); }
195 # tie to enable $rnd_mode to work transparently
196 tie $rnd_mode, 'Math::BigInt';
198 # set up some handy alias names
199 *as_int = \&as_number;
200 *is_pos = \&is_positive;
201 *is_neg = \&is_negative;
204 ##############################################################################
209 # make Class->round_mode() work
211 my $class = ref($self) || $self || __PACKAGE__;
215 if ($m !~ /^(even|odd|\+inf|\-inf|zero|trunc|common)$/)
217 require Carp; Carp::croak ("Unknown round mode '$m'");
219 return ${"${class}::round_mode"} = $m;
221 ${"${class}::round_mode"};
227 # make Class->upgrade() work
229 my $class = ref($self) || $self || __PACKAGE__;
230 # need to set new value?
233 return ${"${class}::upgrade"} = $_[0];
235 ${"${class}::upgrade"};
241 # make Class->downgrade() work
243 my $class = ref($self) || $self || __PACKAGE__;
244 # need to set new value?
247 return ${"${class}::downgrade"} = $_[0];
249 ${"${class}::downgrade"};
255 # make Class->div_scale() work
257 my $class = ref($self) || $self || __PACKAGE__;
262 require Carp; Carp::croak ('div_scale must be greater than zero');
264 ${"${class}::div_scale"} = $_[0];
266 ${"${class}::div_scale"};
271 # $x->accuracy($a); ref($x) $a
272 # $x->accuracy(); ref($x)
273 # Class->accuracy(); class
274 # Class->accuracy($a); class $a
277 my $class = ref($x) || $x || __PACKAGE__;
280 # need to set new value?
284 # convert objects to scalars to avoid deep recursion. If object doesn't
285 # have numify(), then hopefully it will have overloading for int() and
286 # boolean test without wandering into a deep recursion path...
287 $a = $a->numify() if ref($a) && $a->can('numify');
291 # also croak on non-numerical
295 Carp::croak ('Argument to accuracy must be greater than zero');
299 require Carp; Carp::croak ('Argument to accuracy must be an integer');
304 # $object->accuracy() or fallback to global
305 $x->bround($a) if $a; # not for undef, 0
306 $x->{_a} = $a; # set/overwrite, even if not rounded
307 delete $x->{_p}; # clear P
308 $a = ${"${class}::accuracy"} unless defined $a; # proper return value
312 ${"${class}::accuracy"} = $a; # set global A
313 ${"${class}::precision"} = undef; # clear global P
315 return $a; # shortcut
319 # $object->accuracy() or fallback to global
320 $a = $x->{_a} if ref($x);
321 # but don't return global undef, when $x's accuracy is 0!
322 $a = ${"${class}::accuracy"} if !defined $a;
328 # $x->precision($p); ref($x) $p
329 # $x->precision(); ref($x)
330 # Class->precision(); class
331 # Class->precision($p); class $p
334 my $class = ref($x) || $x || __PACKAGE__;
340 # convert objects to scalars to avoid deep recursion. If object doesn't
341 # have numify(), then hopefully it will have overloading for int() and
342 # boolean test without wandering into a deep recursion path...
343 $p = $p->numify() if ref($p) && $p->can('numify');
344 if ((defined $p) && (int($p) != $p))
346 require Carp; Carp::croak ('Argument to precision must be an integer');
350 # $object->precision() or fallback to global
351 $x->bfround($p) if $p; # not for undef, 0
352 $x->{_p} = $p; # set/overwrite, even if not rounded
353 delete $x->{_a}; # clear A
354 $p = ${"${class}::precision"} unless defined $p; # proper return value
358 ${"${class}::precision"} = $p; # set global P
359 ${"${class}::accuracy"} = undef; # clear global A
361 return $p; # shortcut
365 # $object->precision() or fallback to global
366 $p = $x->{_p} if ref($x);
367 # but don't return global undef, when $x's precision is 0!
368 $p = ${"${class}::precision"} if !defined $p;
374 # return (or set) configuration data as hash ref
375 my $class = shift || 'Math::BigInt';
380 # try to set given options as arguments from hash
383 if (ref($args) ne 'HASH')
387 # these values can be "set"
391 upgrade downgrade precision accuracy round_mode div_scale/
394 $set_args->{$key} = $args->{$key} if exists $args->{$key};
395 delete $args->{$key};
400 Carp::croak ("Illegal key(s) '",
401 join("','",keys %$args),"' passed to $class\->config()");
403 foreach my $key (keys %$set_args)
405 if ($key =~ /^trap_(inf|nan)\z/)
407 ${"${class}::_trap_$1"} = ($set_args->{"trap_$1"} ? 1 : 0);
410 # use a call instead of just setting the $variable to check argument
411 $class->$key($set_args->{$key});
415 # now return actual configuration
419 lib_version => ${"${CALC}::VERSION"},
421 trap_nan => ${"${class}::_trap_nan"},
422 trap_inf => ${"${class}::_trap_inf"},
423 version => ${"${class}::VERSION"},
426 upgrade downgrade precision accuracy round_mode div_scale
429 $cfg->{$key} = ${"${class}::$key"};
436 # select accuracy parameter based on precedence,
437 # used by bround() and bfround(), may return undef for scale (means no op)
438 my ($x,$scale,$mode) = @_;
440 $scale = $x->{_a} unless defined $scale;
445 $scale = ${ $class . '::accuracy' } unless defined $scale;
446 $mode = ${ $class . '::round_mode' } unless defined $mode;
453 # select precision parameter based on precedence,
454 # used by bround() and bfround(), may return undef for scale (means no op)
455 my ($x,$scale,$mode) = @_;
457 $scale = $x->{_p} unless defined $scale;
462 $scale = ${ $class . '::precision' } unless defined $scale;
463 $mode = ${ $class . '::round_mode' } unless defined $mode;
468 ##############################################################################
476 # if two arguments, the first one is the class to "swallow" subclasses
484 return unless ref($x); # only for objects
486 my $self = bless {}, $c;
488 $self->{sign} = $x->{sign};
489 $self->{value} = $CALC->_copy($x->{value});
490 $self->{_a} = $x->{_a} if defined $x->{_a};
491 $self->{_p} = $x->{_p} if defined $x->{_p};
497 # create a new BigInt object from a string or another BigInt object.
498 # see hash keys documented at top
500 # the argument could be an object, so avoid ||, && etc on it, this would
501 # cause costly overloaded code to be called. The only allowed ops are
504 my ($class,$wanted,$a,$p,$r) = @_;
506 # avoid numify-calls by not using || on $wanted!
507 return $class->bzero($a,$p) if !defined $wanted; # default to 0
508 return $class->copy($wanted,$a,$p,$r)
509 if ref($wanted) && $wanted->isa($class); # MBI or subclass
511 $class->import() if $IMPORT == 0; # make require work
513 my $self = bless {}, $class;
515 # shortcut for "normal" numbers
516 if ((!ref $wanted) && ($wanted =~ /^([+-]?)[1-9][0-9]*\z/))
518 $self->{sign} = $1 || '+';
520 if ($wanted =~ /^[+-]/)
522 # remove sign without touching wanted to make it work with constants
523 my $t = $wanted; $t =~ s/^[+-]//;
524 $self->{value} = $CALC->_new($t);
528 $self->{value} = $CALC->_new($wanted);
531 if ( (defined $a) || (defined $p)
532 || (defined ${"${class}::precision"})
533 || (defined ${"${class}::accuracy"})
536 $self->round($a,$p,$r) unless (@_ == 4 && !defined $a && !defined $p);
541 # handle '+inf', '-inf' first
542 if ($wanted =~ /^[+-]?inf\z/)
544 $self->{sign} = $wanted; # set a default sign for bstr()
545 return $self->binf($wanted);
547 # split str in m mantissa, e exponent, i integer, f fraction, v value, s sign
548 my ($mis,$miv,$mfv,$es,$ev) = _split($wanted);
553 require Carp; Carp::croak("$wanted is not a number in $class");
555 $self->{value} = $CALC->_zero();
556 $self->{sign} = $nan;
561 # _from_hex or _from_bin
562 $self->{value} = $mis->{value};
563 $self->{sign} = $mis->{sign};
564 return $self; # throw away $mis
566 # make integer from mantissa by adjusting exp, then convert to bigint
567 $self->{sign} = $$mis; # store sign
568 $self->{value} = $CALC->_zero(); # for all the NaN cases
569 my $e = int("$$es$$ev"); # exponent (avoid recursion)
572 my $diff = $e - CORE::length($$mfv);
573 if ($diff < 0) # Not integer
577 require Carp; Carp::croak("$wanted not an integer in $class");
580 return $upgrade->new($wanted,$a,$p,$r) if defined $upgrade;
581 $self->{sign} = $nan;
585 # adjust fraction and add it to value
586 #print "diff > 0 $$miv\n";
587 $$miv = $$miv . ($$mfv . '0' x $diff);
592 if ($$mfv ne '') # e <= 0
594 # fraction and negative/zero E => NOI
597 require Carp; Carp::croak("$wanted not an integer in $class");
599 #print "NOI 2 \$\$mfv '$$mfv'\n";
600 return $upgrade->new($wanted,$a,$p,$r) if defined $upgrade;
601 $self->{sign} = $nan;
605 # xE-y, and empty mfv
608 if ($$miv !~ s/0{$e}$//) # can strip so many zero's?
612 require Carp; Carp::croak("$wanted not an integer in $class");
615 return $upgrade->new($wanted,$a,$p,$r) if defined $upgrade;
616 $self->{sign} = $nan;
620 $self->{sign} = '+' if $$miv eq '0'; # normalize -0 => +0
621 $self->{value} = $CALC->_new($$miv) if $self->{sign} =~ /^[+-]$/;
622 # if any of the globals is set, use them to round and store them inside $self
623 # do not round for new($x,undef,undef) since that is used by MBF to signal
625 $self->round($a,$p,$r) unless @_ == 4 && !defined $a && !defined $p;
631 # create a bigint 'NaN', if given a BigInt, set it to 'NaN'
633 $self = $class if !defined $self;
636 my $c = $self; $self = {}; bless $self, $c;
639 if (${"${class}::_trap_nan"})
642 Carp::croak ("Tried to set $self to NaN in $class\::bnan()");
644 $self->import() if $IMPORT == 0; # make require work
645 return if $self->modify('bnan');
646 if ($self->can('_bnan'))
648 # use subclass to initialize
653 # otherwise do our own thing
654 $self->{value} = $CALC->_zero();
656 $self->{sign} = $nan;
657 delete $self->{_a}; delete $self->{_p}; # rounding NaN is silly
663 # create a bigint '+-inf', if given a BigInt, set it to '+-inf'
664 # the sign is either '+', or if given, used from there
666 my $sign = shift; $sign = '+' if !defined $sign || $sign !~ /^-(inf)?$/;
667 $self = $class if !defined $self;
670 my $c = $self; $self = {}; bless $self, $c;
673 if (${"${class}::_trap_inf"})
676 Carp::croak ("Tried to set $self to +-inf in $class\::binf()");
678 $self->import() if $IMPORT == 0; # make require work
679 return if $self->modify('binf');
680 if ($self->can('_binf'))
682 # use subclass to initialize
687 # otherwise do our own thing
688 $self->{value} = $CALC->_zero();
690 $sign = $sign . 'inf' if $sign !~ /inf$/; # - => -inf
691 $self->{sign} = $sign;
692 ($self->{_a},$self->{_p}) = @_; # take over requested rounding
698 # create a bigint '+0', if given a BigInt, set it to 0
700 $self = __PACKAGE__ if !defined $self;
704 my $c = $self; $self = {}; bless $self, $c;
706 $self->import() if $IMPORT == 0; # make require work
707 return if $self->modify('bzero');
709 if ($self->can('_bzero'))
711 # use subclass to initialize
716 # otherwise do our own thing
717 $self->{value} = $CALC->_zero();
724 # call like: $x->bzero($a,$p,$r,$y);
725 ($self,$self->{_a},$self->{_p}) = $self->_find_round_parameters(@_);
730 if ( (!defined $self->{_a}) || (defined $_[0] && $_[0] > $self->{_a}));
732 if ( (!defined $self->{_p}) || (defined $_[1] && $_[1] > $self->{_p}));
740 # create a bigint '+1' (or -1 if given sign '-'),
741 # if given a BigInt, set it to +1 or -1, respectively
743 my $sign = shift; $sign = '+' if !defined $sign || $sign ne '-';
744 $self = $class if !defined $self;
748 my $c = $self; $self = {}; bless $self, $c;
750 $self->import() if $IMPORT == 0; # make require work
751 return if $self->modify('bone');
753 if ($self->can('_bone'))
755 # use subclass to initialize
760 # otherwise do our own thing
761 $self->{value} = $CALC->_one();
763 $self->{sign} = $sign;
768 # call like: $x->bone($sign,$a,$p,$r,$y);
769 ($self,$self->{_a},$self->{_p}) = $self->_find_round_parameters(@_);
773 # call like: $x->bone($sign,$a,$p,$r);
775 if ( (!defined $self->{_a}) || (defined $_[0] && $_[0] > $self->{_a}));
777 if ( (!defined $self->{_p}) || (defined $_[1] && $_[1] > $self->{_p}));
783 ##############################################################################
784 # string conversation
788 # (ref to BFLOAT or num_str ) return num_str
789 # Convert number from internal format to scientific string format.
790 # internal format is always normalized (no leading zeros, "-0E0" => "+0E0")
791 my ($self,$x) = ref($_[0]) ? (undef,$_[0]) : objectify(1,@_);
793 if ($x->{sign} !~ /^[+-]$/)
795 return $x->{sign} unless $x->{sign} eq '+inf'; # -inf, NaN
798 my ($m,$e) = $x->parts();
799 #$m->bstr() . 'e+' . $e->bstr(); # e can only be positive in BigInt
800 # 'e+' because E can only be positive in BigInt
801 $m->bstr() . 'e+' . $CALC->_str($e->{value});
806 # make a string from bigint object
807 my ($self,$x) = ref($_[0]) ? (undef,$_[0]) : objectify(1,@_);
809 if ($x->{sign} !~ /^[+-]$/)
811 return $x->{sign} unless $x->{sign} eq '+inf'; # -inf, NaN
814 my $es = ''; $es = $x->{sign} if $x->{sign} eq '-';
815 $es.$CALC->_str($x->{value});
820 # Make a "normal" scalar from a BigInt object
821 my $x = shift; $x = $class->new($x) unless ref $x;
823 return $x->bstr() if $x->{sign} !~ /^[+-]$/;
824 my $num = $CALC->_num($x->{value});
825 return -$num if $x->{sign} eq '-';
829 ##############################################################################
830 # public stuff (usually prefixed with "b")
834 # return the sign of the number: +/-/-inf/+inf/NaN
835 my ($self,$x) = ref($_[0]) ? (undef,$_[0]) : objectify(1,@_);
840 sub _find_round_parameters
842 # After any operation or when calling round(), the result is rounded by
843 # regarding the A & P from arguments, local parameters, or globals.
845 # !!!!!!! If you change this, remember to change round(), too! !!!!!!!!!!
847 # This procedure finds the round parameters, but it is for speed reasons
848 # duplicated in round. Otherwise, it is tested by the testsuite and used
851 # returns ($self) or ($self,$a,$p,$r) - sets $self to NaN of both A and P
852 # were requested/defined (locally or globally or both)
854 my ($self,$a,$p,$r,@args) = @_;
855 # $a accuracy, if given by caller
856 # $p precision, if given by caller
857 # $r round_mode, if given by caller
858 # @args all 'other' arguments (0 for unary, 1 for binary ops)
860 my $c = ref($self); # find out class of argument(s)
863 # now pick $a or $p, but only if we have got "arguments"
866 foreach ($self,@args)
868 # take the defined one, or if both defined, the one that is smaller
869 $a = $_->{_a} if (defined $_->{_a}) && (!defined $a || $_->{_a} < $a);
874 # even if $a is defined, take $p, to signal error for both defined
875 foreach ($self,@args)
877 # take the defined one, or if both defined, the one that is bigger
879 $p = $_->{_p} if (defined $_->{_p}) && (!defined $p || $_->{_p} > $p);
882 # if still none defined, use globals (#2)
883 $a = ${"$c\::accuracy"} unless defined $a;
884 $p = ${"$c\::precision"} unless defined $p;
886 # A == 0 is useless, so undef it to signal no rounding
887 $a = undef if defined $a && $a == 0;
890 return ($self) unless defined $a || defined $p; # early out
892 # set A and set P is an fatal error
893 return ($self->bnan()) if defined $a && defined $p; # error
895 $r = ${"$c\::round_mode"} unless defined $r;
896 if ($r !~ /^(even|odd|\+inf|\-inf|zero|trunc|common)$/)
898 require Carp; Carp::croak ("Unknown round mode '$r'");
906 # Round $self according to given parameters, or given second argument's
907 # parameters or global defaults
909 # for speed reasons, _find_round_parameters is embeded here:
911 my ($self,$a,$p,$r,@args) = @_;
912 # $a accuracy, if given by caller
913 # $p precision, if given by caller
914 # $r round_mode, if given by caller
915 # @args all 'other' arguments (0 for unary, 1 for binary ops)
917 my $c = ref($self); # find out class of argument(s)
920 # now pick $a or $p, but only if we have got "arguments"
923 foreach ($self,@args)
925 # take the defined one, or if both defined, the one that is smaller
926 $a = $_->{_a} if (defined $_->{_a}) && (!defined $a || $_->{_a} < $a);
931 # even if $a is defined, take $p, to signal error for both defined
932 foreach ($self,@args)
934 # take the defined one, or if both defined, the one that is bigger
936 $p = $_->{_p} if (defined $_->{_p}) && (!defined $p || $_->{_p} > $p);
939 # if still none defined, use globals (#2)
940 $a = ${"$c\::accuracy"} unless defined $a;
941 $p = ${"$c\::precision"} unless defined $p;
943 # A == 0 is useless, so undef it to signal no rounding
944 $a = undef if defined $a && $a == 0;
947 return $self unless defined $a || defined $p; # early out
949 # set A and set P is an fatal error
950 return $self->bnan() if defined $a && defined $p;
952 $r = ${"$c\::round_mode"} unless defined $r;
953 if ($r !~ /^(even|odd|\+inf|\-inf|zero|trunc|common)$/)
955 require Carp; Carp::croak ("Unknown round mode '$r'");
958 # now round, by calling either fround or ffround:
961 $self->bround($a,$r) if !defined $self->{_a} || $self->{_a} >= $a;
963 else # both can't be undefined due to early out
965 $self->bfround($p,$r) if !defined $self->{_p} || $self->{_p} <= $p;
967 # bround() or bfround() already callled bnorm() if nec.
973 # (numstr or BINT) return BINT
974 # Normalize number -- no-op here
975 my ($self,$x) = ref($_[0]) ? (undef,$_[0]) : objectify(1,@_);
981 # (BINT or num_str) return BINT
982 # make number absolute, or return absolute BINT from string
983 my ($self,$x) = ref($_[0]) ? (undef,$_[0]) : objectify(1,@_);
985 return $x if $x->modify('babs');
986 # post-normalized abs for internal use (does nothing for NaN)
987 $x->{sign} =~ s/^-/+/;
993 # (BINT or num_str) return BINT
994 # negate number or make a negated number from string
995 my ($self,$x) = ref($_[0]) ? (undef,$_[0]) : objectify(1,@_);
997 return $x if $x->modify('bneg');
999 # for +0 dont negate (to have always normalized +0). Does nothing for 'NaN'
1000 $x->{sign} =~ tr/+-/-+/ unless ($x->{sign} eq '+' && $CALC->_is_zero($x->{value}));
1006 # Compares 2 values. Returns one of undef, <0, =0, >0. (suitable for sort)
1007 # (BINT or num_str, BINT or num_str) return cond_code
1010 my ($self,$x,$y) = (ref($_[0]),@_);
1012 # objectify is costly, so avoid it
1013 if ((!ref($_[0])) || (ref($_[0]) ne ref($_[1])))
1015 ($self,$x,$y) = objectify(2,@_);
1018 return $upgrade->bcmp($x,$y) if defined $upgrade &&
1019 ((!$x->isa($self)) || (!$y->isa($self)));
1021 if (($x->{sign} !~ /^[+-]$/) || ($y->{sign} !~ /^[+-]$/))
1023 # handle +-inf and NaN
1024 return undef if (($x->{sign} eq $nan) || ($y->{sign} eq $nan));
1025 return 0 if $x->{sign} eq $y->{sign} && $x->{sign} =~ /^[+-]inf$/;
1026 return +1 if $x->{sign} eq '+inf';
1027 return -1 if $x->{sign} eq '-inf';
1028 return -1 if $y->{sign} eq '+inf';
1031 # check sign for speed first
1032 return 1 if $x->{sign} eq '+' && $y->{sign} eq '-'; # does also 0 <=> -y
1033 return -1 if $x->{sign} eq '-' && $y->{sign} eq '+'; # does also -x <=> 0
1035 # have same sign, so compare absolute values. Don't make tests for zero here
1036 # because it's actually slower than testin in Calc (especially w/ Pari et al)
1038 # post-normalized compare for internal use (honors signs)
1039 if ($x->{sign} eq '+')
1041 # $x and $y both > 0
1042 return $CALC->_acmp($x->{value},$y->{value});
1046 $CALC->_acmp($y->{value},$x->{value}); # swaped acmp (lib returns 0,1,-1)
1051 # Compares 2 values, ignoring their signs.
1052 # Returns one of undef, <0, =0, >0. (suitable for sort)
1053 # (BINT, BINT) return cond_code
1056 my ($self,$x,$y) = (ref($_[0]),@_);
1057 # objectify is costly, so avoid it
1058 if ((!ref($_[0])) || (ref($_[0]) ne ref($_[1])))
1060 ($self,$x,$y) = objectify(2,@_);
1063 return $upgrade->bacmp($x,$y) if defined $upgrade &&
1064 ((!$x->isa($self)) || (!$y->isa($self)));
1066 if (($x->{sign} !~ /^[+-]$/) || ($y->{sign} !~ /^[+-]$/))
1068 # handle +-inf and NaN
1069 return undef if (($x->{sign} eq $nan) || ($y->{sign} eq $nan));
1070 return 0 if $x->{sign} =~ /^[+-]inf$/ && $y->{sign} =~ /^[+-]inf$/;
1071 return 1 if $x->{sign} =~ /^[+-]inf$/ && $y->{sign} !~ /^[+-]inf$/;
1074 $CALC->_acmp($x->{value},$y->{value}); # lib does only 0,1,-1
1079 # add second arg (BINT or string) to first (BINT) (modifies first)
1080 # return result as BINT
1083 my ($self,$x,$y,@r) = (ref($_[0]),@_);
1084 # objectify is costly, so avoid it
1085 if ((!ref($_[0])) || (ref($_[0]) ne ref($_[1])))
1087 ($self,$x,$y,@r) = objectify(2,@_);
1090 return $x if $x->modify('badd');
1091 return $upgrade->badd($upgrade->new($x),$upgrade->new($y),@r) if defined $upgrade &&
1092 ((!$x->isa($self)) || (!$y->isa($self)));
1094 $r[3] = $y; # no push!
1095 # inf and NaN handling
1096 if (($x->{sign} !~ /^[+-]$/) || ($y->{sign} !~ /^[+-]$/))
1099 return $x->bnan() if (($x->{sign} eq $nan) || ($y->{sign} eq $nan));
1101 if (($x->{sign} =~ /^[+-]inf$/) && ($y->{sign} =~ /^[+-]inf$/))
1103 # +inf++inf or -inf+-inf => same, rest is NaN
1104 return $x if $x->{sign} eq $y->{sign};
1107 # +-inf + something => +inf
1108 # something +-inf => +-inf
1109 $x->{sign} = $y->{sign}, return $x if $y->{sign} =~ /^[+-]inf$/;
1113 my ($sx, $sy) = ( $x->{sign}, $y->{sign} ); # get signs
1117 $x->{value} = $CALC->_add($x->{value},$y->{value}); # same sign, abs add
1121 my $a = $CALC->_acmp ($y->{value},$x->{value}); # absolute compare
1124 $x->{value} = $CALC->_sub($y->{value},$x->{value},1); # abs sub w/ swap
1129 # speedup, if equal, set result to 0
1130 $x->{value} = $CALC->_zero();
1135 $x->{value} = $CALC->_sub($x->{value}, $y->{value}); # abs sub
1143 # (BINT or num_str, BINT or num_str) return BINT
1144 # subtract second arg from first, modify first
1147 my ($self,$x,$y,@r) = (ref($_[0]),@_);
1148 # objectify is costly, so avoid it
1149 if ((!ref($_[0])) || (ref($_[0]) ne ref($_[1])))
1151 ($self,$x,$y,@r) = objectify(2,@_);
1154 return $x if $x->modify('bsub');
1156 return $upgrade->new($x)->bsub($upgrade->new($y),@r) if defined $upgrade &&
1157 ((!$x->isa($self)) || (!$y->isa($self)));
1159 return $x->round(@r) if $y->is_zero();
1161 # To correctly handle the lone special case $x->bsub($x), we note the sign
1162 # of $x, then flip the sign from $y, and if the sign of $x did change, too,
1163 # then we caught the special case:
1164 my $xsign = $x->{sign};
1165 $y->{sign} =~ tr/+\-/-+/; # does nothing for NaN
1166 if ($xsign ne $x->{sign})
1168 # special case of $x->bsub($x) results in 0
1169 return $x->bzero(@r) if $xsign =~ /^[+-]$/;
1170 return $x->bnan(); # NaN, -inf, +inf
1172 $x->badd($y,@r); # badd does not leave internal zeros
1173 $y->{sign} =~ tr/+\-/-+/; # refix $y (does nothing for NaN)
1174 $x; # already rounded by badd() or no round nec.
1179 # increment arg by one
1180 my ($self,$x,$a,$p,$r) = ref($_[0]) ? (ref($_[0]),@_) : objectify(1,@_);
1181 return $x if $x->modify('binc');
1183 if ($x->{sign} eq '+')
1185 $x->{value} = $CALC->_inc($x->{value});
1186 return $x->round($a,$p,$r);
1188 elsif ($x->{sign} eq '-')
1190 $x->{value} = $CALC->_dec($x->{value});
1191 $x->{sign} = '+' if $CALC->_is_zero($x->{value}); # -1 +1 => -0 => +0
1192 return $x->round($a,$p,$r);
1194 # inf, nan handling etc
1195 $x->badd($self->bone(),$a,$p,$r); # badd does round
1200 # decrement arg by one
1201 my ($self,$x,@r) = ref($_[0]) ? (ref($_[0]),@_) : objectify(1,@_);
1202 return $x if $x->modify('bdec');
1204 if ($x->{sign} eq '-')
1207 $x->{value} = $CALC->_inc($x->{value});
1211 return $x->badd($self->bone('-'),@r) unless $x->{sign} eq '+'; # inf or NaN
1213 if ($CALC->_is_zero($x->{value}))
1216 $x->{value} = $CALC->_one(); $x->{sign} = '-'; # 0 => -1
1221 $x->{value} = $CALC->_dec($x->{value});
1229 # calculate $x = $a ** $base + $b and return $a (e.g. the log() to base
1233 my ($self,$x,$base,@r) = (undef,@_);
1234 # objectify is costly, so avoid it
1235 if ((!ref($_[0])) || (ref($_[0]) ne ref($_[1])))
1237 ($self,$x,$base,@r) = objectify(1,ref($x),@_);
1240 return $x if $x->modify('blog');
1242 # inf, -inf, NaN, <0 => NaN
1244 if $x->{sign} ne '+' || (defined $base && $base->{sign} ne '+');
1246 return $upgrade->blog($upgrade->new($x),$base,@r) if
1249 # fix for bug #24969:
1250 # the default base is e (Euler's number) which is not an integer
1253 require Math::BigFloat;
1254 my $u = Math::BigFloat->blog(Math::BigFloat->new($x))->as_int();
1255 # modify $x in place
1256 $x->{value} = $u->{value};
1257 $x->{sign} = $u->{sign};
1261 my ($rc,$exact) = $CALC->_log_int($x->{value},$base->{value});
1262 return $x->bnan() unless defined $rc; # not possible to take log?
1269 # (BINT or num_str, BINT or num_str) return BINT
1270 # does not modify arguments, but returns new object
1271 # Lowest Common Multiplicator
1273 my $y = shift; my ($x);
1280 $x = $class->new($y);
1285 my $y = shift; $y = $self->new($y) if !ref ($y);
1293 # (BINT or num_str, BINT or num_str) return BINT
1294 # does not modify arguments, but returns new object
1295 # GCD -- Euclids algorithm, variant C (Knuth Vol 3, pg 341 ff)
1298 $y = $class->new($y) if !ref($y);
1300 my $x = $y->copy()->babs(); # keep arguments
1301 return $x->bnan() if $x->{sign} !~ /^[+-]$/; # x NaN?
1305 $y = shift; $y = $self->new($y) if !ref($y);
1306 return $x->bnan() if $y->{sign} !~ /^[+-]$/; # y NaN?
1307 $x->{value} = $CALC->_gcd($x->{value},$y->{value});
1308 last if $CALC->_is_one($x->{value});
1315 # (num_str or BINT) return BINT
1316 # represent ~x as twos-complement number
1317 # we don't need $self, so undef instead of ref($_[0]) make it slightly faster
1318 my ($self,$x,$a,$p,$r) = ref($_[0]) ? (undef,@_) : objectify(1,@_);
1320 return $x if $x->modify('bnot');
1321 $x->binc()->bneg(); # binc already does round
1324 ##############################################################################
1325 # is_foo test routines
1326 # we don't need $self, so undef instead of ref($_[0]) make it slightly faster
1330 # return true if arg (BINT or num_str) is zero (array '+', '0')
1331 my ($self,$x) = ref($_[0]) ? (undef,$_[0]) : objectify(1,@_);
1333 return 0 if $x->{sign} !~ /^\+$/; # -, NaN & +-inf aren't
1334 $CALC->_is_zero($x->{value});
1339 # return true if arg (BINT or num_str) is NaN
1340 my ($self,$x) = ref($_[0]) ? (undef,$_[0]) : objectify(1,@_);
1342 $x->{sign} eq $nan ? 1 : 0;
1347 # return true if arg (BINT or num_str) is +-inf
1348 my ($self,$x,$sign) = ref($_[0]) ? (undef,@_) : objectify(1,@_);
1352 $sign = '[+-]inf' if $sign eq ''; # +- doesn't matter, only that's inf
1353 $sign = "[$1]inf" if $sign =~ /^([+-])(inf)?$/; # extract '+' or '-'
1354 return $x->{sign} =~ /^$sign$/ ? 1 : 0;
1356 $x->{sign} =~ /^[+-]inf$/ ? 1 : 0; # only +-inf is infinity
1361 # return true if arg (BINT or num_str) is +1, or -1 if sign is given
1362 my ($self,$x,$sign) = ref($_[0]) ? (undef,@_) : objectify(1,@_);
1364 $sign = '+' if !defined $sign || $sign ne '-';
1366 return 0 if $x->{sign} ne $sign; # -1 != +1, NaN, +-inf aren't either
1367 $CALC->_is_one($x->{value});
1372 # return true when arg (BINT or num_str) is odd, false for even
1373 my ($self,$x) = ref($_[0]) ? (undef,$_[0]) : objectify(1,@_);
1375 return 0 if $x->{sign} !~ /^[+-]$/; # NaN & +-inf aren't
1376 $CALC->_is_odd($x->{value});
1381 # return true when arg (BINT or num_str) is even, false for odd
1382 my ($self,$x) = ref($_[0]) ? (undef,$_[0]) : objectify(1,@_);
1384 return 0 if $x->{sign} !~ /^[+-]$/; # NaN & +-inf aren't
1385 $CALC->_is_even($x->{value});
1390 # return true when arg (BINT or num_str) is positive (>= 0)
1391 my ($self,$x) = ref($_[0]) ? (undef,$_[0]) : objectify(1,@_);
1393 return 1 if $x->{sign} eq '+inf'; # +inf is positive
1395 # 0+ is neither positive nor negative
1396 ($x->{sign} eq '+' && !$x->is_zero()) ? 1 : 0;
1401 # return true when arg (BINT or num_str) is negative (< 0)
1402 my ($self,$x) = ref($_[0]) ? (undef,$_[0]) : objectify(1,@_);
1404 $x->{sign} =~ /^-/ ? 1 : 0; # -inf is negative, but NaN is not
1409 # return true when arg (BINT or num_str) is an integer
1410 # always true for BigInt, but different for BigFloats
1411 my ($self,$x) = ref($_[0]) ? (undef,$_[0]) : objectify(1,@_);
1413 $x->{sign} =~ /^[+-]$/ ? 1 : 0; # inf/-inf/NaN aren't
1416 ###############################################################################
1420 # multiply two numbers -- stolen from Knuth Vol 2 pg 233
1421 # (BINT or num_str, BINT or num_str) return BINT
1424 my ($self,$x,$y,@r) = (ref($_[0]),@_);
1425 # objectify is costly, so avoid it
1426 if ((!ref($_[0])) || (ref($_[0]) ne ref($_[1])))
1428 ($self,$x,$y,@r) = objectify(2,@_);
1431 return $x if $x->modify('bmul');
1433 return $x->bnan() if (($x->{sign} eq $nan) || ($y->{sign} eq $nan));
1436 if (($x->{sign} =~ /^[+-]inf$/) || ($y->{sign} =~ /^[+-]inf$/))
1438 return $x->bnan() if $x->is_zero() || $y->is_zero();
1439 # result will always be +-inf:
1440 # +inf * +/+inf => +inf, -inf * -/-inf => +inf
1441 # +inf * -/-inf => -inf, -inf * +/+inf => -inf
1442 return $x->binf() if ($x->{sign} =~ /^\+/ && $y->{sign} =~ /^\+/);
1443 return $x->binf() if ($x->{sign} =~ /^-/ && $y->{sign} =~ /^-/);
1444 return $x->binf('-');
1447 return $upgrade->bmul($x,$upgrade->new($y),@r)
1448 if defined $upgrade && !$y->isa($self);
1450 $r[3] = $y; # no push here
1452 $x->{sign} = $x->{sign} eq $y->{sign} ? '+' : '-'; # +1 * +1 or -1 * -1 => +
1454 $x->{value} = $CALC->_mul($x->{value},$y->{value}); # do actual math
1455 $x->{sign} = '+' if $CALC->_is_zero($x->{value}); # no -0
1462 # helper function that handles +-inf cases for bdiv()/bmod() to reuse code
1463 my ($self,$x,$y) = @_;
1465 # NaN if x == NaN or y == NaN or x==y==0
1466 return wantarray ? ($x->bnan(),$self->bnan()) : $x->bnan()
1467 if (($x->is_nan() || $y->is_nan()) ||
1468 ($x->is_zero() && $y->is_zero()));
1470 # +-inf / +-inf == NaN, reminder also NaN
1471 if (($x->{sign} =~ /^[+-]inf$/) && ($y->{sign} =~ /^[+-]inf$/))
1473 return wantarray ? ($x->bnan(),$self->bnan()) : $x->bnan();
1475 # x / +-inf => 0, remainder x (works even if x == 0)
1476 if ($y->{sign} =~ /^[+-]inf$/)
1478 my $t = $x->copy(); # bzero clobbers up $x
1479 return wantarray ? ($x->bzero(),$t) : $x->bzero()
1482 # 5 / 0 => +inf, -6 / 0 => -inf
1483 # +inf / 0 = inf, inf, and -inf / 0 => -inf, -inf
1484 # exception: -8 / 0 has remainder -8, not 8
1485 # exception: -inf / 0 has remainder -inf, not inf
1488 # +-inf / 0 => special case for -inf
1489 return wantarray ? ($x,$x->copy()) : $x if $x->is_inf();
1490 if (!$x->is_zero() && !$x->is_inf())
1492 my $t = $x->copy(); # binf clobbers up $x
1494 ($x->binf($x->{sign}),$t) : $x->binf($x->{sign})
1498 # last case: +-inf / ordinary number
1500 $sign = '-inf' if substr($x->{sign},0,1) ne $y->{sign};
1502 return wantarray ? ($x,$self->bzero()) : $x;
1507 # (dividend: BINT or num_str, divisor: BINT or num_str) return
1508 # (BINT,BINT) (quo,rem) or BINT (only rem)
1511 my ($self,$x,$y,@r) = (ref($_[0]),@_);
1512 # objectify is costly, so avoid it
1513 if ((!ref($_[0])) || (ref($_[0]) ne ref($_[1])))
1515 ($self,$x,$y,@r) = objectify(2,@_);
1518 return $x if $x->modify('bdiv');
1520 return $self->_div_inf($x,$y)
1521 if (($x->{sign} !~ /^[+-]$/) || ($y->{sign} !~ /^[+-]$/) || $y->is_zero());
1523 return $upgrade->bdiv($upgrade->new($x),$upgrade->new($y),@r)
1524 if defined $upgrade;
1526 $r[3] = $y; # no push!
1528 # calc new sign and in case $y == +/- 1, return $x
1529 my $xsign = $x->{sign}; # keep
1530 $x->{sign} = ($x->{sign} ne $y->{sign} ? '-' : '+');
1534 my $rem = $self->bzero();
1535 ($x->{value},$rem->{value}) = $CALC->_div($x->{value},$y->{value});
1536 $x->{sign} = '+' if $CALC->_is_zero($x->{value});
1537 $rem->{_a} = $x->{_a};
1538 $rem->{_p} = $x->{_p};
1540 if (! $CALC->_is_zero($rem->{value}))
1542 $rem->{sign} = $y->{sign};
1543 $rem = $y->copy()->bsub($rem) if $xsign ne $y->{sign}; # one of them '-'
1547 $rem->{sign} = '+'; # dont leave -0
1553 $x->{value} = $CALC->_div($x->{value},$y->{value});
1554 $x->{sign} = '+' if $CALC->_is_zero($x->{value});
1559 ###############################################################################
1564 # modulus (or remainder)
1565 # (BINT or num_str, BINT or num_str) return BINT
1568 my ($self,$x,$y,@r) = (ref($_[0]),@_);
1569 # objectify is costly, so avoid it
1570 if ((!ref($_[0])) || (ref($_[0]) ne ref($_[1])))
1572 ($self,$x,$y,@r) = objectify(2,@_);
1575 return $x if $x->modify('bmod');
1576 $r[3] = $y; # no push!
1577 if (($x->{sign} !~ /^[+-]$/) || ($y->{sign} !~ /^[+-]$/) || $y->is_zero())
1579 my ($d,$r) = $self->_div_inf($x,$y);
1580 $x->{sign} = $r->{sign};
1581 $x->{value} = $r->{value};
1582 return $x->round(@r);
1585 # calc new sign and in case $y == +/- 1, return $x
1586 $x->{value} = $CALC->_mod($x->{value},$y->{value});
1587 if (!$CALC->_is_zero($x->{value}))
1589 $x->{value} = $CALC->_sub($y->{value},$x->{value},1) # $y-$x
1590 if ($x->{sign} ne $y->{sign});
1591 $x->{sign} = $y->{sign};
1595 $x->{sign} = '+'; # dont leave -0
1602 # Modular inverse. given a number which is (hopefully) relatively
1603 # prime to the modulus, calculate its inverse using Euclid's
1604 # alogrithm. If the number is not relatively prime to the modulus
1605 # (i.e. their gcd is not one) then NaN is returned.
1608 my ($self,$x,$y,@r) = (undef,@_);
1609 # objectify is costly, so avoid it
1610 if ((!ref($_[0])) || (ref($_[0]) ne ref($_[1])))
1612 ($self,$x,$y,@r) = objectify(2,@_);
1615 return $x if $x->modify('bmodinv');
1618 if ($y->{sign} ne '+' # -, NaN, +inf, -inf
1619 || $x->is_zero() # or num == 0
1620 || $x->{sign} !~ /^[+-]$/ # or num NaN, inf, -inf
1623 # put least residue into $x if $x was negative, and thus make it positive
1624 $x->bmod($y) if $x->{sign} eq '-';
1627 ($x->{value},$sign) = $CALC->_modinv($x->{value},$y->{value});
1628 return $x->bnan() if !defined $x->{value}; # in case no GCD found
1629 return $x if !defined $sign; # already real result
1630 $x->{sign} = $sign; # flip/flop see below
1631 $x->bmod($y); # calc real result
1637 # takes a very large number to a very large exponent in a given very
1638 # large modulus, quickly, thanks to binary exponentation. supports
1639 # negative exponents.
1640 my ($self,$num,$exp,$mod,@r) = objectify(3,@_);
1642 return $num if $num->modify('bmodpow');
1644 # check modulus for valid values
1645 return $num->bnan() if ($mod->{sign} ne '+' # NaN, - , -inf, +inf
1646 || $mod->is_zero());
1648 # check exponent for valid values
1649 if ($exp->{sign} =~ /\w/)
1651 # i.e., if it's NaN, +inf, or -inf...
1652 return $num->bnan();
1655 $num->bmodinv ($mod) if ($exp->{sign} eq '-');
1657 # check num for valid values (also NaN if there was no inverse but $exp < 0)
1658 return $num->bnan() if $num->{sign} !~ /^[+-]$/;
1660 # $mod is positive, sign on $exp is ignored, result also positive
1661 $num->{value} = $CALC->_modpow($num->{value},$exp->{value},$mod->{value});
1665 ###############################################################################
1669 # (BINT or num_str, BINT or num_str) return BINT
1670 # compute factorial number from $x, modify $x in place
1671 my ($self,$x,@r) = ref($_[0]) ? (undef,@_) : objectify(1,@_);
1673 return $x if $x->modify('bfac') || $x->{sign} eq '+inf'; # inf => inf
1674 return $x->bnan() if $x->{sign} ne '+'; # NaN, <0 etc => NaN
1676 $x->{value} = $CALC->_fac($x->{value});
1682 # (BINT or num_str, BINT or num_str) return BINT
1683 # compute power of two numbers -- stolen from Knuth Vol 2 pg 233
1684 # modifies first argument
1687 my ($self,$x,$y,@r) = (ref($_[0]),@_);
1688 # objectify is costly, so avoid it
1689 if ((!ref($_[0])) || (ref($_[0]) ne ref($_[1])))
1691 ($self,$x,$y,@r) = objectify(2,@_);
1694 return $x if $x->modify('bpow');
1696 return $x->bnan() if $x->{sign} eq $nan || $y->{sign} eq $nan;
1699 if (($x->{sign} =~ /^[+-]inf$/) || ($y->{sign} =~ /^[+-]inf$/))
1701 if (($x->{sign} =~ /^[+-]inf$/) && ($y->{sign} =~ /^[+-]inf$/))
1707 if ($x->{sign} =~ /^[+-]inf/)
1710 return $x->bnan() if $y->is_zero();
1711 # -inf ** -1 => 1/inf => 0
1712 return $x->bzero() if $y->is_one('-') && $x->is_negative();
1715 return $x if $x->{sign} eq '+inf';
1717 # -inf ** Y => -inf if Y is odd
1718 return $x if $y->is_odd();
1724 return $x if $x->is_one();
1727 return $x if $x->is_zero() && $y->{sign} =~ /^[+]/;
1730 return $x->binf() if $x->is_zero();
1733 return $x->bnan() if $x->is_one('-') && $y->{sign} =~ /^[-]/;
1736 return $x->bzero() if $x->{sign} eq '-' && $y->{sign} =~ /^[-]/;
1739 return $x->bnan() if $x->{sign} eq '-';
1742 return $x->binf() if $y->{sign} =~ /^[+]/;
1747 return $upgrade->bpow($upgrade->new($x),$y,@r)
1748 if defined $upgrade && (!$y->isa($self) || $y->{sign} eq '-');
1750 $r[3] = $y; # no push!
1752 # cases 0 ** Y, X ** 0, X ** 1, 1 ** Y are handled by Calc or Emu
1755 $new_sign = $y->is_odd() ? '-' : '+' if ($x->{sign} ne '+');
1757 # 0 ** -7 => ( 1 / (0 ** 7)) => 1 / 0 => +inf
1759 if $y->{sign} eq '-' && $x->{sign} eq '+' && $CALC->_is_zero($x->{value});
1760 # 1 ** -y => 1 / (1 ** |y|)
1761 # so do test for negative $y after above's clause
1762 return $x->bnan() if $y->{sign} eq '-' && !$CALC->_is_one($x->{value});
1764 $x->{value} = $CALC->_pow($x->{value},$y->{value});
1765 $x->{sign} = $new_sign;
1766 $x->{sign} = '+' if $CALC->_is_zero($y->{value});
1772 # (BINT or num_str, BINT or num_str) return BINT
1773 # compute x << y, base n, y >= 0
1776 my ($self,$x,$y,$n,@r) = (ref($_[0]),@_);
1777 # objectify is costly, so avoid it
1778 if ((!ref($_[0])) || (ref($_[0]) ne ref($_[1])))
1780 ($self,$x,$y,$n,@r) = objectify(2,@_);
1783 return $x if $x->modify('blsft');
1784 return $x->bnan() if ($x->{sign} !~ /^[+-]$/ || $y->{sign} !~ /^[+-]$/);
1785 return $x->round(@r) if $y->is_zero();
1787 $n = 2 if !defined $n; return $x->bnan() if $n <= 0 || $y->{sign} eq '-';
1789 $x->{value} = $CALC->_lsft($x->{value},$y->{value},$n);
1795 # (BINT or num_str, BINT or num_str) return BINT
1796 # compute x >> y, base n, y >= 0
1799 my ($self,$x,$y,$n,@r) = (ref($_[0]),@_);
1800 # objectify is costly, so avoid it
1801 if ((!ref($_[0])) || (ref($_[0]) ne ref($_[1])))
1803 ($self,$x,$y,$n,@r) = objectify(2,@_);
1806 return $x if $x->modify('brsft');
1807 return $x->bnan() if ($x->{sign} !~ /^[+-]$/ || $y->{sign} !~ /^[+-]$/);
1808 return $x->round(@r) if $y->is_zero();
1809 return $x->bzero(@r) if $x->is_zero(); # 0 => 0
1811 $n = 2 if !defined $n; return $x->bnan() if $n <= 0 || $y->{sign} eq '-';
1813 # this only works for negative numbers when shifting in base 2
1814 if (($x->{sign} eq '-') && ($n == 2))
1816 return $x->round(@r) if $x->is_one('-'); # -1 => -1
1819 # although this is O(N*N) in calc (as_bin!) it is O(N) in Pari et al
1820 # but perhaps there is a better emulation for two's complement shift...
1821 # if $y != 1, we must simulate it by doing:
1822 # convert to bin, flip all bits, shift, and be done
1823 $x->binc(); # -3 => -2
1824 my $bin = $x->as_bin();
1825 $bin =~ s/^-0b//; # strip '-0b' prefix
1826 $bin =~ tr/10/01/; # flip bits
1828 if ($y >= CORE::length($bin))
1830 $bin = '0'; # shifting to far right creates -1
1831 # 0, because later increment makes
1832 # that 1, attached '-' makes it '-1'
1833 # because -1 >> x == -1 !
1837 $bin =~ s/.{$y}$//; # cut off at the right side
1838 $bin = '1' . $bin; # extend left side by one dummy '1'
1839 $bin =~ tr/10/01/; # flip bits back
1841 my $res = $self->new('0b'.$bin); # add prefix and convert back
1842 $res->binc(); # remember to increment
1843 $x->{value} = $res->{value}; # take over value
1844 return $x->round(@r); # we are done now, magic, isn't?
1846 # x < 0, n == 2, y == 1
1847 $x->bdec(); # n == 2, but $y == 1: this fixes it
1850 $x->{value} = $CALC->_rsft($x->{value},$y->{value},$n);
1856 #(BINT or num_str, BINT or num_str) return BINT
1860 my ($self,$x,$y,@r) = (ref($_[0]),@_);
1861 # objectify is costly, so avoid it
1862 if ((!ref($_[0])) || (ref($_[0]) ne ref($_[1])))
1864 ($self,$x,$y,@r) = objectify(2,@_);
1867 return $x if $x->modify('band');
1869 $r[3] = $y; # no push!
1871 return $x->bnan() if ($x->{sign} !~ /^[+-]$/ || $y->{sign} !~ /^[+-]$/);
1873 my $sx = $x->{sign} eq '+' ? 1 : -1;
1874 my $sy = $y->{sign} eq '+' ? 1 : -1;
1876 if ($sx == 1 && $sy == 1)
1878 $x->{value} = $CALC->_and($x->{value},$y->{value});
1879 return $x->round(@r);
1882 if ($CAN{signed_and})
1884 $x->{value} = $CALC->_signed_and($x->{value},$y->{value},$sx,$sy);
1885 return $x->round(@r);
1889 __emu_band($self,$x,$y,$sx,$sy,@r);
1894 #(BINT or num_str, BINT or num_str) return BINT
1898 my ($self,$x,$y,@r) = (ref($_[0]),@_);
1899 # objectify is costly, so avoid it
1900 if ((!ref($_[0])) || (ref($_[0]) ne ref($_[1])))
1902 ($self,$x,$y,@r) = objectify(2,@_);
1905 return $x if $x->modify('bior');
1906 $r[3] = $y; # no push!
1908 return $x->bnan() if ($x->{sign} !~ /^[+-]$/ || $y->{sign} !~ /^[+-]$/);
1910 my $sx = $x->{sign} eq '+' ? 1 : -1;
1911 my $sy = $y->{sign} eq '+' ? 1 : -1;
1913 # the sign of X follows the sign of X, e.g. sign of Y irrelevant for bior()
1915 # don't use lib for negative values
1916 if ($sx == 1 && $sy == 1)
1918 $x->{value} = $CALC->_or($x->{value},$y->{value});
1919 return $x->round(@r);
1922 # if lib can do negative values, let it handle this
1923 if ($CAN{signed_or})
1925 $x->{value} = $CALC->_signed_or($x->{value},$y->{value},$sx,$sy);
1926 return $x->round(@r);
1930 __emu_bior($self,$x,$y,$sx,$sy,@r);
1935 #(BINT or num_str, BINT or num_str) return BINT
1939 my ($self,$x,$y,@r) = (ref($_[0]),@_);
1940 # objectify is costly, so avoid it
1941 if ((!ref($_[0])) || (ref($_[0]) ne ref($_[1])))
1943 ($self,$x,$y,@r) = objectify(2,@_);
1946 return $x if $x->modify('bxor');
1947 $r[3] = $y; # no push!
1949 return $x->bnan() if ($x->{sign} !~ /^[+-]$/ || $y->{sign} !~ /^[+-]$/);
1951 my $sx = $x->{sign} eq '+' ? 1 : -1;
1952 my $sy = $y->{sign} eq '+' ? 1 : -1;
1954 # don't use lib for negative values
1955 if ($sx == 1 && $sy == 1)
1957 $x->{value} = $CALC->_xor($x->{value},$y->{value});
1958 return $x->round(@r);
1961 # if lib can do negative values, let it handle this
1962 if ($CAN{signed_xor})
1964 $x->{value} = $CALC->_signed_xor($x->{value},$y->{value},$sx,$sy);
1965 return $x->round(@r);
1969 __emu_bxor($self,$x,$y,$sx,$sy,@r);
1974 my ($self,$x) = ref($_[0]) ? (undef,$_[0]) : objectify(1,@_);
1976 my $e = $CALC->_len($x->{value});
1977 wantarray ? ($e,0) : $e;
1982 # return the nth decimal digit, negative values count backward, 0 is right
1983 my ($self,$x,$n) = ref($_[0]) ? (undef,@_) : objectify(1,@_);
1985 $n = $n->numify() if ref($n);
1986 $CALC->_digit($x->{value},$n||0);
1991 # return the amount of trailing zeros in $x (as scalar)
1993 $x = $class->new($x) unless ref $x;
1995 return 0 if $x->{sign} !~ /^[+-]$/; # NaN, inf, -inf etc
1997 $CALC->_zeros($x->{value}); # must handle odd values, 0 etc
2002 # calculate square root of $x
2003 my ($self,$x,@r) = ref($_[0]) ? (undef,@_) : objectify(1,@_);
2005 return $x if $x->modify('bsqrt');
2007 return $x->bnan() if $x->{sign} !~ /^\+/; # -x or -inf or NaN => NaN
2008 return $x if $x->{sign} eq '+inf'; # sqrt(+inf) == inf
2010 return $upgrade->bsqrt($x,@r) if defined $upgrade;
2012 $x->{value} = $CALC->_sqrt($x->{value});
2018 # calculate $y'th root of $x
2021 my ($self,$x,$y,@r) = (ref($_[0]),@_);
2023 $y = $self->new(2) unless defined $y;
2025 # objectify is costly, so avoid it
2026 if ((!ref($x)) || (ref($x) ne ref($y)))
2028 ($self,$x,$y,@r) = objectify(2,$self || $class,@_);
2031 return $x if $x->modify('broot');
2033 # NaN handling: $x ** 1/0, x or y NaN, or y inf/-inf or y == 0
2034 return $x->bnan() if $x->{sign} !~ /^\+/ || $y->is_zero() ||
2035 $y->{sign} !~ /^\+$/;
2037 return $x->round(@r)
2038 if $x->is_zero() || $x->is_one() || $x->is_inf() || $y->is_one();
2040 return $upgrade->new($x)->broot($upgrade->new($y),@r) if defined $upgrade;
2042 $x->{value} = $CALC->_root($x->{value},$y->{value});
2048 # return a copy of the exponent (here always 0, NaN or 1 for $m == 0)
2049 my ($self,$x) = ref($_[0]) ? (ref($_[0]),$_[0]) : objectify(1,@_);
2051 if ($x->{sign} !~ /^[+-]$/)
2053 my $s = $x->{sign}; $s =~ s/^[+-]//; # NaN, -inf,+inf => NaN or inf
2054 return $self->new($s);
2056 return $self->bone() if $x->is_zero();
2058 $self->new($x->_trailing_zeros());
2063 # return the mantissa (compatible to Math::BigFloat, e.g. reduced)
2064 my ($self,$x) = ref($_[0]) ? (ref($_[0]),$_[0]) : objectify(1,@_);
2066 if ($x->{sign} !~ /^[+-]$/)
2068 # for NaN, +inf, -inf: keep the sign
2069 return $self->new($x->{sign});
2071 my $m = $x->copy(); delete $m->{_p}; delete $m->{_a};
2072 # that's a bit inefficient:
2073 my $zeros = $m->_trailing_zeros();
2074 $m->brsft($zeros,10) if $zeros != 0;
2080 # return a copy of both the exponent and the mantissa
2081 my ($self,$x) = ref($_[0]) ? (undef,$_[0]) : objectify(1,@_);
2083 ($x->mantissa(),$x->exponent());
2086 ##############################################################################
2087 # rounding functions
2091 # precision: round to the $Nth digit left (+$n) or right (-$n) from the '.'
2092 # $n == 0 || $n == 1 => round to integer
2093 my $x = shift; my $self = ref($x) || $x; $x = $self->new($x) unless ref $x;
2095 my ($scale,$mode) = $x->_scale_p(@_);
2097 return $x if !defined $scale || $x->modify('bfround'); # no-op
2099 # no-op for BigInts if $n <= 0
2100 $x->bround( $x->length()-$scale, $mode) if $scale > 0;
2102 delete $x->{_a}; # delete to save memory
2103 $x->{_p} = $scale; # store new _p
2107 sub _scan_for_nonzero
2109 # internal, used by bround() to scan for non-zeros after a '5'
2110 my ($x,$pad,$xs,$len) = @_;
2112 return 0 if $len == 1; # "5" is trailed by invisible zeros
2113 my $follow = $pad - 1;
2114 return 0 if $follow > $len || $follow < 1;
2116 # use the string form to check whether only '0's follow or not
2117 substr ($xs,-$follow) =~ /[^0]/ ? 1 : 0;
2122 # Exists to make life easier for switch between MBF and MBI (should we
2123 # autoload fxxx() like MBF does for bxxx()?)
2124 my $x = shift; $x = $class->new($x) unless ref $x;
2130 # accuracy: +$n preserve $n digits from left,
2131 # -$n preserve $n digits from right (f.i. for 0.1234 style in MBF)
2133 # and overwrite the rest with 0's, return normalized number
2134 # do not return $x->bnorm(), but $x
2136 my $x = shift; $x = $class->new($x) unless ref $x;
2137 my ($scale,$mode) = $x->_scale_a(@_);
2138 return $x if !defined $scale || $x->modify('bround'); # no-op
2140 if ($x->is_zero() || $scale == 0)
2142 $x->{_a} = $scale if !defined $x->{_a} || $x->{_a} > $scale; # 3 > 2
2145 return $x if $x->{sign} !~ /^[+-]$/; # inf, NaN
2147 # we have fewer digits than we want to scale to
2148 my $len = $x->length();
2149 # convert $scale to a scalar in case it is an object (put's a limit on the
2150 # number length, but this would already limited by memory constraints), makes
2152 $scale = $scale->numify() if ref ($scale);
2154 # scale < 0, but > -len (not >=!)
2155 if (($scale < 0 && $scale < -$len-1) || ($scale >= $len))
2157 $x->{_a} = $scale if !defined $x->{_a} || $x->{_a} > $scale; # 3 > 2
2161 # count of 0's to pad, from left (+) or right (-): 9 - +6 => 3, or |-6| => 6
2162 my ($pad,$digit_round,$digit_after);
2163 $pad = $len - $scale;
2164 $pad = abs($scale-1) if $scale < 0;
2166 # do not use digit(), it is very costly for binary => decimal
2167 # getting the entire string is also costly, but we need to do it only once
2168 my $xs = $CALC->_str($x->{value});
2171 # pad: 123: 0 => -1, at 1 => -2, at 2 => -3, at 3 => -4
2172 # pad+1: 123: 0 => 0, at 1 => -1, at 2 => -2, at 3 => -3
2173 $digit_round = '0'; $digit_round = substr($xs,$pl,1) if $pad <= $len;
2174 $pl++; $pl ++ if $pad >= $len;
2175 $digit_after = '0'; $digit_after = substr($xs,$pl,1) if $pad > 0;
2177 # in case of 01234 we round down, for 6789 up, and only in case 5 we look
2178 # closer at the remaining digits of the original $x, remember decision
2179 my $round_up = 1; # default round up
2181 ($mode eq 'trunc') || # trunc by round down
2182 ($digit_after =~ /[01234]/) || # round down anyway,
2184 ($digit_after eq '5') && # not 5000...0000
2185 ($x->_scan_for_nonzero($pad,$xs,$len) == 0) &&
2187 ($mode eq 'even') && ($digit_round =~ /[24680]/) ||
2188 ($mode eq 'odd') && ($digit_round =~ /[13579]/) ||
2189 ($mode eq '+inf') && ($x->{sign} eq '-') ||
2190 ($mode eq '-inf') && ($x->{sign} eq '+') ||
2191 ($mode eq 'zero') # round down if zero, sign adjusted below
2193 my $put_back = 0; # not yet modified
2195 if (($pad > 0) && ($pad <= $len))
2197 substr($xs,-$pad,$pad) = '0' x $pad; # replace with '00...'
2198 $put_back = 1; # need to put back
2202 $x->bzero(); # round to '0'
2205 if ($round_up) # what gave test above?
2207 $put_back = 1; # need to put back
2208 $pad = $len, $xs = '0' x $pad if $scale < 0; # tlr: whack 0.51=>1.0
2210 # we modify directly the string variant instead of creating a number and
2211 # adding it, since that is faster (we already have the string)
2212 my $c = 0; $pad ++; # for $pad == $len case
2213 while ($pad <= $len)
2215 $c = substr($xs,-$pad,1) + 1; $c = '0' if $c eq '10';
2216 substr($xs,-$pad,1) = $c; $pad++;
2217 last if $c != 0; # no overflow => early out
2219 $xs = '1'.$xs if $c == 0;
2222 $x->{value} = $CALC->_new($xs) if $put_back == 1; # put back, if needed
2224 $x->{_a} = $scale if $scale >= 0;
2227 $x->{_a} = $len+$scale;
2228 $x->{_a} = 0 if $scale < -$len;
2235 # return integer less or equal then number; no-op since it's already integer
2236 my ($self,$x,@r) = ref($_[0]) ? (undef,@_) : objectify(1,@_);
2243 # return integer greater or equal then number; no-op since it's already int
2244 my ($self,$x,@r) = ref($_[0]) ? (undef,@_) : objectify(1,@_);
2251 # An object might be asked to return itself as bigint on certain overloaded
2252 # operations. This does exactly this, so that sub classes can simple inherit
2253 # it or override with their own integer conversion routine.
2259 # return as hex string, with prefixed 0x
2260 my $x = shift; $x = $class->new($x) if !ref($x);
2262 return $x->bstr() if $x->{sign} !~ /^[+-]$/; # inf, nan etc
2265 $s = $x->{sign} if $x->{sign} eq '-';
2266 $s . $CALC->_as_hex($x->{value});
2271 # return as binary string, with prefixed 0b
2272 my $x = shift; $x = $class->new($x) if !ref($x);
2274 return $x->bstr() if $x->{sign} !~ /^[+-]$/; # inf, nan etc
2276 my $s = ''; $s = $x->{sign} if $x->{sign} eq '-';
2277 return $s . $CALC->_as_bin($x->{value});
2282 # return as octal string, with prefixed 0
2283 my $x = shift; $x = $class->new($x) if !ref($x);
2285 return $x->bstr() if $x->{sign} !~ /^[+-]$/; # inf, nan etc
2287 my $s = ''; $s = $x->{sign} if $x->{sign} eq '-';
2288 return $s . $CALC->_as_oct($x->{value});
2291 ##############################################################################
2292 # private stuff (internal use only)
2296 # check for strings, if yes, return objects instead
2298 # the first argument is number of args objectify() should look at it will
2299 # return $count+1 elements, the first will be a classname. This is because
2300 # overloaded '""' calls bstr($object,undef,undef) and this would result in
2301 # useless objects being created and thrown away. So we cannot simple loop
2302 # over @_. If the given count is 0, all arguments will be used.
2304 # If the second arg is a ref, use it as class.
2305 # If not, try to use it as classname, unless undef, then use $class
2306 # (aka Math::BigInt). The latter shouldn't happen,though.
2309 # $x->badd(1); => ref x, scalar y
2310 # Class->badd(1,2); => classname x (scalar), scalar x, scalar y
2311 # Class->badd( Class->(1),2); => classname x (scalar), ref x, scalar y
2312 # Math::BigInt::badd(1,2); => scalar x, scalar y
2313 # In the last case we check number of arguments to turn it silently into
2314 # $class,1,2. (We can not take '1' as class ;o)
2315 # badd($class,1) is not supported (it should, eventually, try to add undef)
2316 # currently it tries 'Math::BigInt' + 1, which will not work.
2318 # some shortcut for the common cases
2320 return (ref($_[1]),$_[1]) if (@_ == 2) && ($_[0]||0 == 1) && ref($_[1]);
2322 my $count = abs(shift || 0);
2324 my (@a,$k,$d); # resulting array, temp, and downgrade
2327 # okay, got object as first
2332 # nope, got 1,2 (Class->xxx(1) => Class,1 and not supported)
2334 $a[0] = shift if $_[0] =~ /^[A-Z].*::/; # classname as first?
2338 # disable downgrading, because Math::BigFLoat->foo('1.0','2.0') needs floats
2339 if (defined ${"$a[0]::downgrade"})
2341 $d = ${"$a[0]::downgrade"};
2342 ${"$a[0]::downgrade"} = undef;
2345 my $up = ${"$a[0]::upgrade"};
2346 #print "Now in objectify, my class is today $a[0], count = $count\n";
2354 $k = $a[0]->new($k);
2356 elsif (!defined $up && ref($k) ne $a[0])
2358 # foreign object, try to convert to integer
2359 $k->can('as_number') ? $k = $k->as_number() : $k = $a[0]->new($k);
2372 $k = $a[0]->new($k);
2374 elsif (!defined $up && ref($k) ne $a[0])
2376 # foreign object, try to convert to integer
2377 $k->can('as_number') ? $k = $k->as_number() : $k = $a[0]->new($k);
2381 push @a,@_; # return other params, too
2385 require Carp; Carp::croak ("$class objectify needs list context");
2387 ${"$a[0]::downgrade"} = $d;
2391 sub _register_callback
2393 my ($class,$callback) = @_;
2395 if (ref($callback) ne 'CODE')
2398 Carp::croak ("$callback is not a coderef");
2400 $CALLBACKS{$class} = $callback;
2407 $IMPORT++; # remember we did import()
2408 my @a; my $l = scalar @_;
2409 my $warn_or_die = 0; # 0 - no warn, 1 - warn, 2 - die
2410 for ( my $i = 0; $i < $l ; $i++ )
2412 if ($_[$i] eq ':constant')
2414 # this causes overlord er load to step in
2416 integer => sub { $self->new(shift) },
2417 binary => sub { $self->new(shift) };
2419 elsif ($_[$i] eq 'upgrade')
2421 # this causes upgrading
2422 $upgrade = $_[$i+1]; # or undef to disable
2425 elsif ($_[$i] =~ /^(lib|try|only)\z/)
2427 # this causes a different low lib to take care...
2428 $CALC = $_[$i+1] || '';
2429 # lib => 1 (warn on fallback), try => 0 (no warn), only => 2 (die on fallback)
2430 $warn_or_die = 1 if $_[$i] eq 'lib';
2431 $warn_or_die = 2 if $_[$i] eq 'only';
2439 # any non :constant stuff is handled by our parent, Exporter
2444 $self->SUPER::import(@a); # need it for subclasses
2445 $self->export_to_level(1,$self,@a); # need it for MBF
2448 # try to load core math lib
2449 my @c = split /\s*,\s*/,$CALC;
2452 $_ =~ tr/a-zA-Z0-9://cd; # limit to sane characters
2454 push @c, \'FastCalc', \'Calc' # if all fail, try these
2455 if $warn_or_die < 2; # but not for "only"
2456 $CALC = ''; # signal error
2459 # fallback libraries are "marked" as \'string', extract string if nec.
2460 my $lib = $l; $lib = $$l if ref($l);
2462 next if ($lib || '') eq '';
2463 $lib = 'Math::BigInt::'.$lib if $lib !~ /^Math::BigInt/i;
2467 # Perl < 5.6.0 dies with "out of memory!" when eval("") and ':constant' is
2468 # used in the same script, or eval("") inside import().
2469 my @parts = split /::/, $lib; # Math::BigInt => Math BigInt
2470 my $file = pop @parts; $file .= '.pm'; # BigInt => BigInt.pm
2472 $file = File::Spec->catfile (@parts, $file);
2473 eval { require "$file"; $lib->import( @c ); }
2477 eval "use $lib qw/@c/;";
2482 # loaded it ok, see if the api_version() is high enough
2483 if ($lib->can('api_version') && $lib->api_version() >= 1.0)
2486 # api_version matches, check if it really provides anything we need
2490 add mul div sub dec inc
2491 acmp len digit is_one is_zero is_even is_odd
2493 zeros new copy check
2494 from_hex from_oct from_bin as_hex as_bin as_oct
2495 rsft lsft xor and or
2496 mod sqrt root fac pow modinv modpow log_int gcd
2499 if (!$lib->can("_$method"))
2501 if (($WARN{$lib}||0) < 2)
2504 Carp::carp ("$lib is missing method '_$method'");
2505 $WARN{$lib} = 1; # still warn about the lib
2514 if ($warn_or_die > 0 && ref($l))
2517 my $msg = "Math::BigInt: couldn't load specified math lib(s), fallback to $lib";
2518 Carp::carp ($msg) if $warn_or_die == 1;
2519 Carp::croak ($msg) if $warn_or_die == 2;
2521 last; # found a usable one, break
2525 if (($WARN{$lib}||0) < 2)
2527 my $ver = eval "\$$lib\::VERSION" || 'unknown';
2529 Carp::carp ("Cannot load outdated $lib v$ver, please upgrade");
2530 $WARN{$lib} = 2; # never warn again
2538 if ($warn_or_die == 2)
2540 Carp::croak ("Couldn't load specified math lib(s) and fallback disallowed");
2544 Carp::croak ("Couldn't load any math lib(s), not even fallback to Calc.pm");
2549 foreach my $class (keys %CALLBACKS)
2551 &{$CALLBACKS{$class}}($CALC);
2554 # Fill $CAN with the results of $CALC->can(...) for emulating lower math lib
2558 for my $method (qw/ signed_and signed_or signed_xor /)
2560 $CAN{$method} = $CALC->can("_$method") ? 1 : 0;
2568 # create a bigint from a hexadecimal string
2569 my ($self, $hs) = @_;
2571 my $rc = $self->__from_hex($hs);
2573 return $self->bnan() unless defined $rc;
2580 # create a bigint from a hexadecimal string
2581 my ($self, $bs) = @_;
2583 my $rc = $self->__from_bin($bs);
2585 return $self->bnan() unless defined $rc;
2592 # create a bigint from a hexadecimal string
2593 my ($self, $os) = @_;
2595 my $x = $self->bzero();
2598 $os =~ s/([0-9a-fA-F])_([0-9a-fA-F])/$1$2/g;
2599 $os =~ s/([0-9a-fA-F])_([0-9a-fA-F])/$1$2/g;
2601 return $x->bnan() if $os !~ /^[\-\+]?0[0-9]+$/;
2603 my $sign = '+'; $sign = '-' if $os =~ /^-/;
2605 $os =~ s/^[+-]//; # strip sign
2606 $x->{value} = $CALC->_from_oct($os);
2607 $x->{sign} = $sign unless $CALC->_is_zero($x->{value}); # no '-0'
2614 # convert a (ref to) big hex string to BigInt, return undef for error
2617 my $x = Math::BigInt->bzero();
2620 $hs =~ s/([0-9a-fA-F])_([0-9a-fA-F])/$1$2/g;
2621 $hs =~ s/([0-9a-fA-F])_([0-9a-fA-F])/$1$2/g;
2623 return $x->bnan() if $hs !~ /^[\-\+]?0x[0-9A-Fa-f]+$/;
2625 my $sign = '+'; $sign = '-' if $hs =~ /^-/;
2627 $hs =~ s/^[+-]//; # strip sign
2628 $x->{value} = $CALC->_from_hex($hs);
2629 $x->{sign} = $sign unless $CALC->_is_zero($x->{value}); # no '-0'
2636 # convert a (ref to) big binary string to BigInt, return undef for error
2639 my $x = Math::BigInt->bzero();
2642 $bs =~ s/([01])_([01])/$1$2/g;
2643 $bs =~ s/([01])_([01])/$1$2/g;
2644 return $x->bnan() if $bs !~ /^[+-]?0b[01]+$/;
2646 my $sign = '+'; $sign = '-' if $bs =~ /^\-/;
2647 $bs =~ s/^[+-]//; # strip sign
2649 $x->{value} = $CALC->_from_bin($bs);
2650 $x->{sign} = $sign unless $CALC->_is_zero($x->{value}); # no '-0'
2656 # input: num_str; output: undef for invalid or
2657 # (\$mantissa_sign,\$mantissa_value,\$mantissa_fraction,\$exp_sign,\$exp_value)
2658 # Internal, take apart a string and return the pieces.
2659 # Strip leading/trailing whitespace, leading zeros, underscore and reject
2663 # strip white space at front, also extranous leading zeros
2664 $x =~ s/^\s*([-]?)0*([0-9])/$1$2/g; # will not strip ' .2'
2665 $x =~ s/^\s+//; # but this will
2666 $x =~ s/\s+$//g; # strip white space at end
2668 # shortcut, if nothing to split, return early
2669 if ($x =~ /^[+-]?[0-9]+\z/)
2671 $x =~ s/^([+-])0*([0-9])/$2/; my $sign = $1 || '+';
2672 return (\$sign, \$x, \'', \'', \0);
2675 # invalid starting char?
2676 return if $x !~ /^[+-]?(\.?[0-9]|0b[0-1]|0x[0-9a-fA-F])/;
2678 return __from_hex($x) if $x =~ /^[\-\+]?0x/; # hex string
2679 return __from_bin($x) if $x =~ /^[\-\+]?0b/; # binary string
2681 # strip underscores between digits
2682 $x =~ s/([0-9])_([0-9])/$1$2/g;
2683 $x =~ s/([0-9])_([0-9])/$1$2/g; # do twice for 1_2_3
2685 # some possible inputs:
2686 # 2.1234 # 0.12 # 1 # 1E1 # 2.134E1 # 434E-10 # 1.02009E-2
2687 # .2 # 1_2_3.4_5_6 # 1.4E1_2_3 # 1e3 # +.2 # 0e999
2689 my ($m,$e,$last) = split /[Ee]/,$x;
2690 return if defined $last; # last defined => 1e2E3 or others
2691 $e = '0' if !defined $e || $e eq "";
2693 # sign,value for exponent,mantint,mantfrac
2694 my ($es,$ev,$mis,$miv,$mfv);
2696 if ($e =~ /^([+-]?)0*([0-9]+)$/) # strip leading zeros
2700 return if $m eq '.' || $m eq '';
2701 my ($mi,$mf,$lastf) = split /\./,$m;
2702 return if defined $lastf; # lastf defined => 1.2.3 or others
2703 $mi = '0' if !defined $mi;
2704 $mi .= '0' if $mi =~ /^[\-\+]?$/;
2705 $mf = '0' if !defined $mf || $mf eq '';
2706 if ($mi =~ /^([+-]?)0*([0-9]+)$/) # strip leading zeros
2708 $mis = $1||'+'; $miv = $2;
2709 return unless ($mf =~ /^([0-9]*?)0*$/); # strip trailing zeros
2711 # handle the 0e999 case here
2712 $ev = 0 if $miv eq '0' && $mfv eq '';
2713 return (\$mis,\$miv,\$mfv,\$es,\$ev);
2716 return; # NaN, not a number
2719 ##############################################################################
2720 # internal calculation routines (others are in Math::BigInt::Calc etc)
2724 # (BINT or num_str, BINT or num_str) return BINT
2725 # does modify first argument
2729 return $x->bnan() if ($x->{sign} eq $nan) || ($ty->{sign} eq $nan);
2730 my $method = ref($x) . '::bgcd';
2732 $x * $ty / &$method($x,$ty);
2735 ###############################################################################
2736 # this method returns 0 if the object can be modified, or 1 if not.
2737 # We use a fast constant sub() here, to avoid costly calls. Subclasses
2738 # may override it with special code (f.i. Math::BigInt::Constant does so)
2740 sub modify () { 0; }
2749 Math::BigInt - Arbitrary size integer/float math package
2755 # or make it faster: install (optional) Math::BigInt::GMP
2756 # and always use (it will fall back to pure Perl if the
2757 # GMP library is not installed):
2759 # will warn if Math::BigInt::GMP cannot be found
2760 use Math::BigInt lib => 'GMP';
2762 # to supress the warning use this:
2763 # use Math::BigInt try => 'GMP';
2765 my $str = '1234567890';
2766 my @values = (64,74,18);
2767 my $n = 1; my $sign = '-';
2770 $x = Math::BigInt->new($str); # defaults to 0
2771 $y = $x->copy(); # make a true copy
2772 $nan = Math::BigInt->bnan(); # create a NotANumber
2773 $zero = Math::BigInt->bzero(); # create a +0
2774 $inf = Math::BigInt->binf(); # create a +inf
2775 $inf = Math::BigInt->binf('-'); # create a -inf
2776 $one = Math::BigInt->bone(); # create a +1
2777 $one = Math::BigInt->bone('-'); # create a -1
2779 $h = Math::BigInt->new('0x123'); # from hexadecimal
2780 $b = Math::BigInt->new('0b101'); # from binary
2781 $o = Math::BigInt->from_oct('0101'); # from octal
2783 # Testing (don't modify their arguments)
2784 # (return true if the condition is met, otherwise false)
2786 $x->is_zero(); # if $x is +0
2787 $x->is_nan(); # if $x is NaN
2788 $x->is_one(); # if $x is +1
2789 $x->is_one('-'); # if $x is -1
2790 $x->is_odd(); # if $x is odd
2791 $x->is_even(); # if $x is even
2792 $x->is_pos(); # if $x >= 0
2793 $x->is_neg(); # if $x < 0
2794 $x->is_inf($sign); # if $x is +inf, or -inf (sign is default '+')
2795 $x->is_int(); # if $x is an integer (not a float)
2797 # comparing and digit/sign extraction
2798 $x->bcmp($y); # compare numbers (undef,<0,=0,>0)
2799 $x->bacmp($y); # compare absolutely (undef,<0,=0,>0)
2800 $x->sign(); # return the sign, either +,- or NaN
2801 $x->digit($n); # return the nth digit, counting from right
2802 $x->digit(-$n); # return the nth digit, counting from left
2804 # The following all modify their first argument. If you want to preserve
2805 # $x, use $z = $x->copy()->bXXX($y); See under L<CAVEATS> for why this is
2806 # necessary when mixing $a = $b assignments with non-overloaded math.
2808 $x->bzero(); # set $x to 0
2809 $x->bnan(); # set $x to NaN
2810 $x->bone(); # set $x to +1
2811 $x->bone('-'); # set $x to -1
2812 $x->binf(); # set $x to inf
2813 $x->binf('-'); # set $x to -inf
2815 $x->bneg(); # negation
2816 $x->babs(); # absolute value
2817 $x->bnorm(); # normalize (no-op in BigInt)
2818 $x->bnot(); # two's complement (bit wise not)
2819 $x->binc(); # increment $x by 1
2820 $x->bdec(); # decrement $x by 1
2822 $x->badd($y); # addition (add $y to $x)
2823 $x->bsub($y); # subtraction (subtract $y from $x)
2824 $x->bmul($y); # multiplication (multiply $x by $y)
2825 $x->bdiv($y); # divide, set $x to quotient
2826 # return (quo,rem) or quo if scalar
2828 $x->bmod($y); # modulus (x % y)
2829 $x->bmodpow($exp,$mod); # modular exponentation (($num**$exp) % $mod))
2830 $x->bmodinv($mod); # the inverse of $x in the given modulus $mod
2832 $x->bpow($y); # power of arguments (x ** y)
2833 $x->blsft($y); # left shift in base 10
2834 $x->brsft($y); # right shift in base 10
2835 # returns (quo,rem) or quo if in scalar context
2836 $x->blsft($y,$n); # left shift by $y places in base $n
2837 $x->brsft($y,$n); # right shift by $y places in base $n
2838 # returns (quo,rem) or quo if in scalar context
2840 $x->band($y); # bitwise and
2841 $x->bior($y); # bitwise inclusive or
2842 $x->bxor($y); # bitwise exclusive or
2843 $x->bnot(); # bitwise not (two's complement)
2845 $x->bsqrt(); # calculate square-root
2846 $x->broot($y); # $y'th root of $x (e.g. $y == 3 => cubic root)
2847 $x->bfac(); # factorial of $x (1*2*3*4*..$x)
2849 $x->round($A,$P,$mode); # round to accuracy or precision using mode $mode
2850 $x->bround($n); # accuracy: preserve $n digits
2851 $x->bfround($n); # round to $nth digit, no-op for BigInts
2853 # The following do not modify their arguments in BigInt (are no-ops),
2854 # but do so in BigFloat:
2856 $x->bfloor(); # return integer less or equal than $x
2857 $x->bceil(); # return integer greater or equal than $x
2859 # The following do not modify their arguments:
2861 # greatest common divisor (no OO style)
2862 my $gcd = Math::BigInt::bgcd(@values);
2863 # lowest common multiplicator (no OO style)
2864 my $lcm = Math::BigInt::blcm(@values);
2866 $x->length(); # return number of digits in number
2867 ($xl,$f) = $x->length(); # length of number and length of fraction part,
2868 # latter is always 0 digits long for BigInts
2870 $x->exponent(); # return exponent as BigInt
2871 $x->mantissa(); # return (signed) mantissa as BigInt
2872 $x->parts(); # return (mantissa,exponent) as BigInt
2873 $x->copy(); # make a true copy of $x (unlike $y = $x;)
2874 $x->as_int(); # return as BigInt (in BigInt: same as copy())
2875 $x->numify(); # return as scalar (might overflow!)
2877 # conversation to string (do not modify their argument)
2878 $x->bstr(); # normalized string (e.g. '3')
2879 $x->bsstr(); # norm. string in scientific notation (e.g. '3E0')
2880 $x->as_hex(); # as signed hexadecimal string with prefixed 0x
2881 $x->as_bin(); # as signed binary string with prefixed 0b
2882 $x->as_oct(); # as signed octal string with prefixed 0
2885 # precision and accuracy (see section about rounding for more)
2886 $x->precision(); # return P of $x (or global, if P of $x undef)
2887 $x->precision($n); # set P of $x to $n
2888 $x->accuracy(); # return A of $x (or global, if A of $x undef)
2889 $x->accuracy($n); # set A $x to $n
2892 Math::BigInt->precision(); # get/set global P for all BigInt objects
2893 Math::BigInt->accuracy(); # get/set global A for all BigInt objects
2894 Math::BigInt->round_mode(); # get/set global round mode, one of
2895 # 'even', 'odd', '+inf', '-inf', 'zero', 'trunc' or 'common'
2896 Math::BigInt->config(); # return hash containing configuration
2900 All operators (including basic math operations) are overloaded if you
2901 declare your big integers as
2903 $i = new Math::BigInt '123_456_789_123_456_789';
2905 Operations with overloaded operators preserve the arguments which is
2906 exactly what you expect.
2912 Input values to these routines may be any string, that looks like a number
2913 and results in an integer, including hexadecimal and binary numbers.
2915 Scalars holding numbers may also be passed, but note that non-integer numbers
2916 may already have lost precision due to the conversation to float. Quote
2917 your input if you want BigInt to see all the digits:
2919 $x = Math::BigInt->new(12345678890123456789); # bad
2920 $x = Math::BigInt->new('12345678901234567890'); # good
2922 You can include one underscore between any two digits.
2924 This means integer values like 1.01E2 or even 1000E-2 are also accepted.
2925 Non-integer values result in NaN.
2927 Hexadecimal (prefixed with "0x") and binary numbers (prefixed with "0b")
2928 are accepted, too. Please note that octal numbers are not recognized
2929 by new(), so the following will print "123":
2931 perl -MMath::BigInt -le 'print Math::BigInt->new("0123")'
2933 To convert an octal number, use from_oct();
2935 perl -MMath::BigInt -le 'print Math::BigInt->from_oct("0123")'
2937 Currently, Math::BigInt::new() defaults to 0, while Math::BigInt::new('')
2938 results in 'NaN'. This might change in the future, so use always the following
2939 explicit forms to get a zero or NaN:
2941 $zero = Math::BigInt->bzero();
2942 $nan = Math::BigInt->bnan();
2944 C<bnorm()> on a BigInt object is now effectively a no-op, since the numbers
2945 are always stored in normalized form. If passed a string, creates a BigInt
2946 object from the input.
2950 Output values are BigInt objects (normalized), except for the methods which
2951 return a string (see L<SYNOPSIS>).
2953 Some routines (C<is_odd()>, C<is_even()>, C<is_zero()>, C<is_one()>,
2954 C<is_nan()>, etc.) return true or false, while others (C<bcmp()>, C<bacmp()>)
2955 return either undef (if NaN is involved), <0, 0 or >0 and are suited for sort.
2961 Each of the methods below (except config(), accuracy() and precision())
2962 accepts three additional parameters. These arguments C<$A>, C<$P> and C<$R>
2963 are C<accuracy>, C<precision> and C<round_mode>. Please see the section about
2964 L<ACCURACY and PRECISION> for more information.
2970 print Dumper ( Math::BigInt->config() );
2971 print Math::BigInt->config()->{lib},"\n";
2973 Returns a hash containing the configuration, e.g. the version number, lib
2974 loaded etc. The following hash keys are currently filled in with the
2975 appropriate information.
2979 ============================================================
2980 lib Name of the low-level math library
2982 lib_version Version of low-level math library (see 'lib')
2984 class The class name of config() you just called
2986 upgrade To which class math operations might be upgraded
2988 downgrade To which class math operations might be downgraded
2990 precision Global precision
2992 accuracy Global accuracy
2994 round_mode Global round mode
2996 version version number of the class you used
2998 div_scale Fallback accuracy for div
3000 trap_nan If true, traps creation of NaN via croak()
3002 trap_inf If true, traps creation of +inf/-inf via croak()
3005 The following values can be set by passing C<config()> a reference to a hash:
3008 upgrade downgrade precision accuracy round_mode div_scale
3012 $new_cfg = Math::BigInt->config( { trap_inf => 1, precision => 5 } );
3016 $x->accuracy(5); # local for $x
3017 CLASS->accuracy(5); # global for all members of CLASS
3018 # Note: This also applies to new()!
3020 $A = $x->accuracy(); # read out accuracy that affects $x
3021 $A = CLASS->accuracy(); # read out global accuracy
3023 Set or get the global or local accuracy, aka how many significant digits the
3024 results have. If you set a global accuracy, then this also applies to new()!
3026 Warning! The accuracy I<sticks>, e.g. once you created a number under the
3027 influence of C<< CLASS->accuracy($A) >>, all results from math operations with
3028 that number will also be rounded.
3030 In most cases, you should probably round the results explicitly using one of
3031 L<round()>, L<bround()> or L<bfround()> or by passing the desired accuracy
3032 to the math operation as additional parameter:
3034 my $x = Math::BigInt->new(30000);
3035 my $y = Math::BigInt->new(7);
3036 print scalar $x->copy()->bdiv($y, 2); # print 4300
3037 print scalar $x->copy()->bdiv($y)->bround(2); # print 4300
3039 Please see the section about L<ACCURACY AND PRECISION> for further details.
3041 Value must be greater than zero. Pass an undef value to disable it:
3043 $x->accuracy(undef);
3044 Math::BigInt->accuracy(undef);
3046 Returns the current accuracy. For C<$x->accuracy()> it will return either the
3047 local accuracy, or if not defined, the global. This means the return value
3048 represents the accuracy that will be in effect for $x:
3050 $y = Math::BigInt->new(1234567); # unrounded
3051 print Math::BigInt->accuracy(4),"\n"; # set 4, print 4
3052 $x = Math::BigInt->new(123456); # $x will be automatically rounded!
3053 print "$x $y\n"; # '123500 1234567'
3054 print $x->accuracy(),"\n"; # will be 4
3055 print $y->accuracy(),"\n"; # also 4, since global is 4
3056 print Math::BigInt->accuracy(5),"\n"; # set to 5, print 5
3057 print $x->accuracy(),"\n"; # still 4
3058 print $y->accuracy(),"\n"; # 5, since global is 5
3060 Note: Works also for subclasses like Math::BigFloat. Each class has it's own
3061 globals separated from Math::BigInt, but it is possible to subclass
3062 Math::BigInt and make the globals of the subclass aliases to the ones from
3067 $x->precision(-2); # local for $x, round at the second digit right of the dot
3068 $x->precision(2); # ditto, round at the second digit left of the dot
3070 CLASS->precision(5); # Global for all members of CLASS
3071 # This also applies to new()!
3072 CLASS->precision(-5); # ditto
3074 $P = CLASS->precision(); # read out global precision
3075 $P = $x->precision(); # read out precision that affects $x
3077 Note: You probably want to use L<accuracy()> instead. With L<accuracy> you
3078 set the number of digits each result should have, with L<precision> you
3079 set the place where to round!
3081 C<precision()> sets or gets the global or local precision, aka at which digit
3082 before or after the dot to round all results. A set global precision also
3083 applies to all newly created numbers!
3085 In Math::BigInt, passing a negative number precision has no effect since no
3086 numbers have digits after the dot. In L<Math::BigFloat>, it will round all
3087 results to P digits after the dot.
3089 Please see the section about L<ACCURACY AND PRECISION> for further details.
3091 Pass an undef value to disable it:
3093 $x->precision(undef);
3094 Math::BigInt->precision(undef);
3096 Returns the current precision. For C<$x->precision()> it will return either the
3097 local precision of $x, or if not defined, the global. This means the return
3098 value represents the prevision that will be in effect for $x:
3100 $y = Math::BigInt->new(1234567); # unrounded
3101 print Math::BigInt->precision(4),"\n"; # set 4, print 4
3102 $x = Math::BigInt->new(123456); # will be automatically rounded
3103 print $x; # print "120000"!
3105 Note: Works also for subclasses like L<Math::BigFloat>. Each class has its
3106 own globals separated from Math::BigInt, but it is possible to subclass
3107 Math::BigInt and make the globals of the subclass aliases to the ones from
3114 Shifts $x right by $y in base $n. Default is base 2, used are usually 10 and
3115 2, but others work, too.
3117 Right shifting usually amounts to dividing $x by $n ** $y and truncating the
3121 $x = Math::BigInt->new(10);
3122 $x->brsft(1); # same as $x >> 1: 5
3123 $x = Math::BigInt->new(1234);
3124 $x->brsft(2,10); # result 12
3126 There is one exception, and that is base 2 with negative $x:
3129 $x = Math::BigInt->new(-5);
3132 This will print -3, not -2 (as it would if you divide -5 by 2 and truncate the
3137 $x = Math::BigInt->new($str,$A,$P,$R);
3139 Creates a new BigInt object from a scalar or another BigInt object. The
3140 input is accepted as decimal, hex (with leading '0x') or binary (with leading
3143 See L<Input> for more info on accepted input formats.
3147 $x = Math::BigIn->from_oct("0775"); # input is octal
3151 $x = Math::BigIn->from_hex("0xcafe"); # input is hexadecimal
3155 $x = Math::BigIn->from_oct("0x10011"); # input is binary
3159 $x = Math::BigInt->bnan();
3161 Creates a new BigInt object representing NaN (Not A Number).
3162 If used on an object, it will set it to NaN:
3168 $x = Math::BigInt->bzero();
3170 Creates a new BigInt object representing zero.
3171 If used on an object, it will set it to zero:
3177 $x = Math::BigInt->binf($sign);
3179 Creates a new BigInt object representing infinity. The optional argument is
3180 either '-' or '+', indicating whether you want infinity or minus infinity.
3181 If used on an object, it will set it to infinity:
3188 $x = Math::BigInt->binf($sign);
3190 Creates a new BigInt object representing one. The optional argument is
3191 either '-' or '+', indicating whether you want one or minus one.
3192 If used on an object, it will set it to one:
3197 =head2 is_one()/is_zero()/is_nan()/is_inf()
3200 $x->is_zero(); # true if arg is +0
3201 $x->is_nan(); # true if arg is NaN
3202 $x->is_one(); # true if arg is +1
3203 $x->is_one('-'); # true if arg is -1
3204 $x->is_inf(); # true if +inf
3205 $x->is_inf('-'); # true if -inf (sign is default '+')
3207 These methods all test the BigInt for being one specific value and return
3208 true or false depending on the input. These are faster than doing something
3213 =head2 is_pos()/is_neg()/is_positive()/is_negative()
3215 $x->is_pos(); # true if > 0
3216 $x->is_neg(); # true if < 0
3218 The methods return true if the argument is positive or negative, respectively.
3219 C<NaN> is neither positive nor negative, while C<+inf> counts as positive, and
3220 C<-inf> is negative. A C<zero> is neither positive nor negative.
3222 These methods are only testing the sign, and not the value.
3224 C<is_positive()> and C<is_negative()> are aliases to C<is_pos()> and
3225 C<is_neg()>, respectively. C<is_positive()> and C<is_negative()> were
3226 introduced in v1.36, while C<is_pos()> and C<is_neg()> were only introduced
3229 =head2 is_odd()/is_even()/is_int()
3231 $x->is_odd(); # true if odd, false for even
3232 $x->is_even(); # true if even, false for odd
3233 $x->is_int(); # true if $x is an integer
3235 The return true when the argument satisfies the condition. C<NaN>, C<+inf>,
3236 C<-inf> are not integers and are neither odd nor even.
3238 In BigInt, all numbers except C<NaN>, C<+inf> and C<-inf> are integers.
3244 Compares $x with $y and takes the sign into account.
3245 Returns -1, 0, 1 or undef.
3251 Compares $x with $y while ignoring their. Returns -1, 0, 1 or undef.
3257 Return the sign, of $x, meaning either C<+>, C<->, C<-inf>, C<+inf> or NaN.
3259 If you want $x to have a certain sign, use one of the following methods:
3262 $x->babs()->bneg(); # '-'
3264 $x->binf(); # '+inf'
3265 $x->binf('-'); # '-inf'
3269 $x->digit($n); # return the nth digit, counting from right
3271 If C<$n> is negative, returns the digit counting from left.
3277 Negate the number, e.g. change the sign between '+' and '-', or between '+inf'
3278 and '-inf', respectively. Does nothing for NaN or zero.
3284 Set the number to it's absolute value, e.g. change the sign from '-' to '+'
3285 and from '-inf' to '+inf', respectively. Does nothing for NaN or positive
3290 $x->bnorm(); # normalize (no-op)
3296 Two's complement (bit wise not). This is equivalent to
3304 $x->binc(); # increment x by 1
3308 $x->bdec(); # decrement x by 1
3312 $x->badd($y); # addition (add $y to $x)
3316 $x->bsub($y); # subtraction (subtract $y from $x)
3320 $x->bmul($y); # multiplication (multiply $x by $y)
3324 $x->bdiv($y); # divide, set $x to quotient
3325 # return (quo,rem) or quo if scalar
3329 $x->bmod($y); # modulus (x % y)
3333 num->bmodinv($mod); # modular inverse
3335 Returns the inverse of C<$num> in the given modulus C<$mod>. 'C<NaN>' is
3336 returned unless C<$num> is relatively prime to C<$mod>, i.e. unless
3337 C<bgcd($num, $mod)==1>.
3341 $num->bmodpow($exp,$mod); # modular exponentation
3342 # ($num**$exp % $mod)
3344 Returns the value of C<$num> taken to the power C<$exp> in the modulus
3345 C<$mod> using binary exponentation. C<bmodpow> is far superior to
3350 because it is much faster - it reduces internal variables into
3351 the modulus whenever possible, so it operates on smaller numbers.
3353 C<bmodpow> also supports negative exponents.
3355 bmodpow($num, -1, $mod)
3357 is exactly equivalent to
3363 $x->bpow($y); # power of arguments (x ** y)
3367 $x->blsft($y); # left shift
3368 $x->blsft($y,$n); # left shift, in base $n (like 10)
3372 $x->brsft($y); # right shift
3373 $x->brsft($y,$n); # right shift, in base $n (like 10)
3377 $x->band($y); # bitwise and
3381 $x->bior($y); # bitwise inclusive or
3385 $x->bxor($y); # bitwise exclusive or
3389 $x->bnot(); # bitwise not (two's complement)
3393 $x->bsqrt(); # calculate square-root
3397 $x->bfac(); # factorial of $x (1*2*3*4*..$x)
3401 $x->round($A,$P,$round_mode);
3403 Round $x to accuracy C<$A> or precision C<$P> using the round mode
3408 $x->bround($N); # accuracy: preserve $N digits
3412 $x->bfround($N); # round to $Nth digit, no-op for BigInts
3418 Set $x to the integer less or equal than $x. This is a no-op in BigInt, but
3419 does change $x in BigFloat.
3425 Set $x to the integer greater or equal than $x. This is a no-op in BigInt, but
3426 does change $x in BigFloat.
3430 bgcd(@values); # greatest common divisor (no OO style)
3434 blcm(@values); # lowest common multiplicator (no OO style)
3439 ($xl,$fl) = $x->length();
3441 Returns the number of digits in the decimal representation of the number.
3442 In list context, returns the length of the integer and fraction part. For
3443 BigInt's, the length of the fraction part will always be 0.
3449 Return the exponent of $x as BigInt.
3455 Return the signed mantissa of $x as BigInt.
3459 $x->parts(); # return (mantissa,exponent) as BigInt
3463 $x->copy(); # make a true copy of $x (unlike $y = $x;)
3465 =head2 as_int()/as_number()
3469 Returns $x as a BigInt (truncated towards zero). In BigInt this is the same as
3472 C<as_number()> is an alias to this method. C<as_number> was introduced in
3473 v1.22, while C<as_int()> was only introduced in v1.68.
3479 Returns a normalized string representation of C<$x>.
3483 $x->bsstr(); # normalized string in scientific notation
3487 $x->as_hex(); # as signed hexadecimal string with prefixed 0x
3491 $x->as_bin(); # as signed binary string with prefixed 0b
3495 $x->as_oct(); # as signed octal string with prefixed 0
3501 This returns a normal Perl scalar from $x. It is used automatically
3502 whenever a scalar is needed, for instance in array index operations.
3504 This loses precision, to avoid this use L<as_int()> instead.
3508 $x->modify('bpowd');
3510 This method returns 0 if the object can be modified with the given
3511 peration, or 1 if not.
3513 This is used for instance by L<Math::BigInt::Constant>.
3515 =head2 upgrade()/downgrade()
3517 Set/get the class for downgrade/upgrade operations. Thuis is used
3518 for instance by L<bignum>. The defaults are '', thus the following
3519 operation will create a BigInt, not a BigFloat:
3521 my $i = Math::BigInt->new(123);
3522 my $f = Math::BigFloat->new('123.1');
3524 print $i + $f,"\n"; # print 246
3528 Set/get the number of digits for the default precision in divide
3533 Set/get the current round mode.
3535 =head1 ACCURACY and PRECISION
3537 Since version v1.33, Math::BigInt and Math::BigFloat have full support for
3538 accuracy and precision based rounding, both automatically after every
3539 operation, as well as manually.
3541 This section describes the accuracy/precision handling in Math::Big* as it
3542 used to be and as it is now, complete with an explanation of all terms and
3545 Not yet implemented things (but with correct description) are marked with '!',
3546 things that need to be answered are marked with '?'.
3548 In the next paragraph follows a short description of terms used here (because
3549 these may differ from terms used by others people or documentation).
3551 During the rest of this document, the shortcuts A (for accuracy), P (for
3552 precision), F (fallback) and R (rounding mode) will be used.
3556 A fixed number of digits before (positive) or after (negative)
3557 the decimal point. For example, 123.45 has a precision of -2. 0 means an
3558 integer like 123 (or 120). A precision of 2 means two digits to the left
3559 of the decimal point are zero, so 123 with P = 1 becomes 120. Note that
3560 numbers with zeros before the decimal point may have different precisions,
3561 because 1200 can have p = 0, 1 or 2 (depending on what the inital value
3562 was). It could also have p < 0, when the digits after the decimal point
3565 The string output (of floating point numbers) will be padded with zeros:
3567 Initial value P A Result String
3568 ------------------------------------------------------------
3569 1234.01 -3 1000 1000
3572 1234.001 1 1234 1234.0
3574 1234.01 2 1234.01 1234.01
3575 1234.01 5 1234.01 1234.01000
3577 For BigInts, no padding occurs.
3581 Number of significant digits. Leading zeros are not counted. A
3582 number may have an accuracy greater than the non-zero digits
3583 when there are zeros in it or trailing zeros. For example, 123.456 has
3584 A of 6, 10203 has 5, 123.0506 has 7, 123.450000 has 8 and 0.000123 has 3.
3586 The string output (of floating point numbers) will be padded with zeros:
3588 Initial value P A Result String
3589 ------------------------------------------------------------
3591 1234.01 6 1234.01 1234.01
3592 1234.1 8 1234.1 1234.1000
3594 For BigInts, no padding occurs.
3598 When both A and P are undefined, this is used as a fallback accuracy when
3601 =head2 Rounding mode R
3603 When rounding a number, different 'styles' or 'kinds'
3604 of rounding are possible. (Note that random rounding, as in
3605 Math::Round, is not implemented.)
3611 truncation invariably removes all digits following the
3612 rounding place, replacing them with zeros. Thus, 987.65 rounded
3613 to tens (P=1) becomes 980, and rounded to the fourth sigdig
3614 becomes 987.6 (A=4). 123.456 rounded to the second place after the
3615 decimal point (P=-2) becomes 123.46.
3617 All other implemented styles of rounding attempt to round to the
3618 "nearest digit." If the digit D immediately to the right of the
3619 rounding place (skipping the decimal point) is greater than 5, the
3620 number is incremented at the rounding place (possibly causing a
3621 cascade of incrementation): e.g. when rounding to units, 0.9 rounds
3622 to 1, and -19.9 rounds to -20. If D < 5, the number is similarly
3623 truncated at the rounding place: e.g. when rounding to units, 0.4
3624 rounds to 0, and -19.4 rounds to -19.
3626 However the results of other styles of rounding differ if the
3627 digit immediately to the right of the rounding place (skipping the
3628 decimal point) is 5 and if there are no digits, or no digits other
3629 than 0, after that 5. In such cases:
3633 rounds the digit at the rounding place to 0, 2, 4, 6, or 8
3634 if it is not already. E.g., when rounding to the first sigdig, 0.45
3635 becomes 0.4, -0.55 becomes -0.6, but 0.4501 becomes 0.5.
3639 rounds the digit at the rounding place to 1, 3, 5, 7, or 9 if
3640 it is not already. E.g., when rounding to the first sigdig, 0.45
3641 becomes 0.5, -0.55 becomes -0.5, but 0.5501 becomes 0.6.
3645 round to plus infinity, i.e. always round up. E.g., when
3646 rounding to the first sigdig, 0.45 becomes 0.5, -0.55 becomes -0.5,
3647 and 0.4501 also becomes 0.5.
3651 round to minus infinity, i.e. always round down. E.g., when
3652 rounding to the first sigdig, 0.45 becomes 0.4, -0.55 becomes -0.6,
3653 but 0.4501 becomes 0.5.
3657 round to zero, i.e. positive numbers down, negative ones up.
3658 E.g., when rounding to the first sigdig, 0.45 becomes 0.4, -0.55
3659 becomes -0.5, but 0.4501 becomes 0.5.
3663 round up if the digit immediately to the right of the rounding place
3664 is 5 or greater, otherwise round down. E.g., 0.15 becomes 0.2 and
3669 The handling of A & P in MBI/MBF (the old core code shipped with Perl
3670 versions <= 5.7.2) is like this:
3676 * ffround($p) is able to round to $p number of digits after the decimal
3678 * otherwise P is unused
3680 =item Accuracy (significant digits)
3682 * fround($a) rounds to $a significant digits
3683 * only fdiv() and fsqrt() take A as (optional) paramater
3684 + other operations simply create the same number (fneg etc), or more (fmul)
3686 + rounding/truncating is only done when explicitly calling one of fround
3687 or ffround, and never for BigInt (not implemented)
3688 * fsqrt() simply hands its accuracy argument over to fdiv.
3689 * the documentation and the comment in the code indicate two different ways
3690 on how fdiv() determines the maximum number of digits it should calculate,
3691 and the actual code does yet another thing
3693 max($Math::BigFloat::div_scale,length(dividend)+length(divisor))
3695 result has at most max(scale, length(dividend), length(divisor)) digits
3697 scale = max(scale, length(dividend)-1,length(divisor)-1);
3698 scale += length(divisor) - length(dividend);
3699 So for lx = 3, ly = 9, scale = 10, scale will actually be 16 (10+9-3).
3700 Actually, the 'difference' added to the scale is calculated from the
3701 number of "significant digits" in dividend and divisor, which is derived
3702 by looking at the length of the mantissa. Which is wrong, since it includes
3703 the + sign (oops) and actually gets 2 for '+100' and 4 for '+101'. Oops
3704 again. Thus 124/3 with div_scale=1 will get you '41.3' based on the strange
3705 assumption that 124 has 3 significant digits, while 120/7 will get you
3706 '17', not '17.1' since 120 is thought to have 2 significant digits.
3707 The rounding after the division then uses the remainder and $y to determine
3708 wether it must round up or down.
3709 ? I have no idea which is the right way. That's why I used a slightly more
3710 ? simple scheme and tweaked the few failing testcases to match it.
3714 This is how it works now:
3718 =item Setting/Accessing
3720 * You can set the A global via C<< Math::BigInt->accuracy() >> or
3721 C<< Math::BigFloat->accuracy() >> or whatever class you are using.
3722 * You can also set P globally by using C<< Math::SomeClass->precision() >>
3724 * Globals are classwide, and not inherited by subclasses.
3725 * to undefine A, use C<< Math::SomeCLass->accuracy(undef); >>
3726 * to undefine P, use C<< Math::SomeClass->precision(undef); >>
3727 * Setting C<< Math::SomeClass->accuracy() >> clears automatically
3728 C<< Math::SomeClass->precision() >>, and vice versa.
3729 * To be valid, A must be > 0, P can have any value.
3730 * If P is negative, this means round to the P'th place to the right of the
3731 decimal point; positive values mean to the left of the decimal point.
3732 P of 0 means round to integer.
3733 * to find out the current global A, use C<< Math::SomeClass->accuracy() >>
3734 * to find out the current global P, use C<< Math::SomeClass->precision() >>
3735 * use C<< $x->accuracy() >> respective C<< $x->precision() >> for the local
3736 setting of C<< $x >>.
3737 * Please note that C<< $x->accuracy() >> respective C<< $x->precision() >>
3738 return eventually defined global A or P, when C<< $x >>'s A or P is not
3741 =item Creating numbers
3743 * When you create a number, you can give it's desired A or P via:
3744 $x = Math::BigInt->new($number,$A,$P);
3745 * Only one of A or P can be defined, otherwise the result is NaN
3746 * If no A or P is give ($x = Math::BigInt->new($number) form), then the
3747 globals (if set) will be used. Thus changing the global defaults later on
3748 will not change the A or P of previously created numbers (i.e., A and P of
3749 $x will be what was in effect when $x was created)
3750 * If given undef for A and P, B<no> rounding will occur, and the globals will
3751 B<not> be used. This is used by subclasses to create numbers without
3752 suffering rounding in the parent. Thus a subclass is able to have it's own
3753 globals enforced upon creation of a number by using
3754 C<< $x = Math::BigInt->new($number,undef,undef) >>:
3756 use Math::BigInt::SomeSubclass;
3759 Math::BigInt->accuracy(2);
3760 Math::BigInt::SomeSubClass->accuracy(3);
3761 $x = Math::BigInt::SomeSubClass->new(1234);
3763 $x is now 1230, and not 1200. A subclass might choose to implement
3764 this otherwise, e.g. falling back to the parent's A and P.
3768 * If A or P are enabled/defined, they are used to round the result of each
3769 operation according to the rules below
3770 * Negative P is ignored in Math::BigInt, since BigInts never have digits
3771 after the decimal point
3772 * Math::BigFloat uses Math::BigInt internally, but setting A or P inside
3773 Math::BigInt as globals does not tamper with the parts of a BigFloat.
3774 A flag is used to mark all Math::BigFloat numbers as 'never round'.
3778 * It only makes sense that a number has only one of A or P at a time.
3779 If you set either A or P on one object, or globally, the other one will
3780 be automatically cleared.
3781 * If two objects are involved in an operation, and one of them has A in
3782 effect, and the other P, this results in an error (NaN).
3783 * A takes precedence over P (Hint: A comes before P).
3784 If neither of them is defined, nothing is used, i.e. the result will have
3785 as many digits as it can (with an exception for fdiv/fsqrt) and will not
3787 * There is another setting for fdiv() (and thus for fsqrt()). If neither of
3788 A or P is defined, fdiv() will use a fallback (F) of $div_scale digits.
3789 If either the dividend's or the divisor's mantissa has more digits than
3790 the value of F, the higher value will be used instead of F.
3791 This is to limit the digits (A) of the result (just consider what would
3792 happen with unlimited A and P in the case of 1/3 :-)
3793 * fdiv will calculate (at least) 4 more digits than required (determined by
3794 A, P or F), and, if F is not used, round the result
3795 (this will still fail in the case of a result like 0.12345000000001 with A
3796 or P of 5, but this can not be helped - or can it?)
3797 * Thus you can have the math done by on Math::Big* class in two modi:
3798 + never round (this is the default):
3799 This is done by setting A and P to undef. No math operation
3800 will round the result, with fdiv() and fsqrt() as exceptions to guard
3801 against overflows. You must explicitly call bround(), bfround() or
3802 round() (the latter with parameters).
3803 Note: Once you have rounded a number, the settings will 'stick' on it
3804 and 'infect' all other numbers engaged in math operations with it, since
3805 local settings have the highest precedence. So, to get SaferRound[tm],
3806 use a copy() before rounding like this:
3808 $x = Math::BigFloat->new(12.34);
3809 $y = Math::BigFloat->new(98.76);
3810 $z = $x * $y; # 1218.6984
3811 print $x->copy()->fround(3); # 12.3 (but A is now 3!)
3812 $z = $x * $y; # still 1218.6984, without
3813 # copy would have been 1210!
3815 + round after each op:
3816 After each single operation (except for testing like is_zero()), the
3817 method round() is called and the result is rounded appropriately. By
3818 setting proper values for A and P, you can have all-the-same-A or
3819 all-the-same-P modes. For example, Math::Currency might set A to undef,
3820 and P to -2, globally.
3822 ?Maybe an extra option that forbids local A & P settings would be in order,
3823 ?so that intermediate rounding does not 'poison' further math?
3825 =item Overriding globals
3827 * you will be able to give A, P and R as an argument to all the calculation
3828 routines; the second parameter is A, the third one is P, and the fourth is
3829 R (shift right by one for binary operations like badd). P is used only if
3830 the first parameter (A) is undefined. These three parameters override the
3831 globals in the order detailed as follows, i.e. the first defined value
3833 (local: per object, global: global default, parameter: argument to sub)
3836 + local A (if defined on both of the operands: smaller one is taken)
3837 + local P (if defined on both of the operands: bigger one is taken)
3841 * fsqrt() will hand its arguments to fdiv(), as it used to, only now for two
3842 arguments (A and P) instead of one
3844 =item Local settings
3846 * You can set A or P locally by using C<< $x->accuracy() >> or
3847 C<< $x->precision() >>
3848 and thus force different A and P for different objects/numbers.
3849 * Setting A or P this way immediately rounds $x to the new value.
3850 * C<< $x->accuracy() >> clears C<< $x->precision() >>, and vice versa.
3854 * the rounding routines will use the respective global or local settings.
3855 fround()/bround() is for accuracy rounding, while ffround()/bfround()
3857 * the two rounding functions take as the second parameter one of the
3858 following rounding modes (R):
3859 'even', 'odd', '+inf', '-inf', 'zero', 'trunc', 'common'
3860 * you can set/get the global R by using C<< Math::SomeClass->round_mode() >>
3861 or by setting C<< $Math::SomeClass::round_mode >>
3862 * after each operation, C<< $result->round() >> is called, and the result may
3863 eventually be rounded (that is, if A or P were set either locally,
3864 globally or as parameter to the operation)
3865 * to manually round a number, call C<< $x->round($A,$P,$round_mode); >>
3866 this will round the number by using the appropriate rounding function
3867 and then normalize it.
3868 * rounding modifies the local settings of the number:
3870 $x = Math::BigFloat->new(123.456);
3874 Here 4 takes precedence over 5, so 123.5 is the result and $x->accuracy()
3875 will be 4 from now on.
3877 =item Default values
3886 * The defaults are set up so that the new code gives the same results as
3887 the old code (except in a few cases on fdiv):
3888 + Both A and P are undefined and thus will not be used for rounding
3889 after each operation.
3890 + round() is thus a no-op, unless given extra parameters A and P
3894 =head1 Infinity and Not a Number
3896 While BigInt has extensive handling of inf and NaN, certain quirks remain.
3902 These perl routines currently (as of Perl v.5.8.6) cannot handle passed
3905 te@linux:~> perl -wle 'print 2 ** 3333'
3907 te@linux:~> perl -wle 'print 2 ** 3333 == 2 ** 3333'
3909 te@linux:~> perl -wle 'print oct(2 ** 3333)'
3911 te@linux:~> perl -wle 'print hex(2 ** 3333)'
3912 Illegal hexadecimal digit 'i' ignored at -e line 1.
3915 The same problems occur if you pass them Math::BigInt->binf() objects. Since
3916 overloading these routines is not possible, this cannot be fixed from BigInt.
3918 =item ==, !=, <, >, <=, >= with NaNs
3920 BigInt's bcmp() routine currently returns undef to signal that a NaN was
3921 involved in a comparison. However, the overload code turns that into
3922 either 1 or '' and thus operations like C<< NaN != NaN >> might return
3927 C<< log(-inf) >> is highly weird. Since log(-x)=pi*i+log(x), then
3928 log(-inf)=pi*i+inf. However, since the imaginary part is finite, the real
3929 infinity "overshadows" it, so the number might as well just be infinity.
3930 However, the result is a complex number, and since BigInt/BigFloat can only
3931 have real numbers as results, the result is NaN.
3933 =item exp(), cos(), sin(), atan2()
3935 These all might have problems handling infinity right.
3941 The actual numbers are stored as unsigned big integers (with seperate sign).
3943 You should neither care about nor depend on the internal representation; it
3944 might change without notice. Use B<ONLY> method calls like C<< $x->sign(); >>
3945 instead relying on the internal representation.
3949 Math with the numbers is done (by default) by a module called
3950 C<Math::BigInt::Calc>. This is equivalent to saying:
3952 use Math::BigInt lib => 'Calc';
3954 You can change this by using:
3956 use Math::BigInt lib => 'BitVect';
3958 The following would first try to find Math::BigInt::Foo, then
3959 Math::BigInt::Bar, and when this also fails, revert to Math::BigInt::Calc:
3961 use Math::BigInt lib => 'Foo,Math::BigInt::Bar';
3963 Since Math::BigInt::GMP is in almost all cases faster than Calc (especially in
3964 math involving really big numbers, where it is B<much> faster), and there is
3965 no penalty if Math::BigInt::GMP is not installed, it is a good idea to always
3968 use Math::BigInt lib => 'GMP';
3970 Different low-level libraries use different formats to store the
3971 numbers. You should B<NOT> depend on the number having a specific format
3974 See the respective math library module documentation for further details.
3978 The sign is either '+', '-', 'NaN', '+inf' or '-inf'.
3980 A sign of 'NaN' is used to represent the result when input arguments are not
3981 numbers or as a result of 0/0. '+inf' and '-inf' represent plus respectively
3982 minus infinity. You will get '+inf' when dividing a positive number by 0, and
3983 '-inf' when dividing any negative number by 0.
3985 =head2 mantissa(), exponent() and parts()
3987 C<mantissa()> and C<exponent()> return the said parts of the BigInt such
3990 $m = $x->mantissa();
3991 $e = $x->exponent();
3992 $y = $m * ( 10 ** $e );
3993 print "ok\n" if $x == $y;
3995 C<< ($m,$e) = $x->parts() >> is just a shortcut that gives you both of them
3996 in one go. Both the returned mantissa and exponent have a sign.
3998 Currently, for BigInts C<$e> is always 0, except +inf and -inf, where it is
3999 C<+inf>; and for NaN, where it is C<NaN>; and for C<$x == 0>, where it is C<1>
4000 (to be compatible with Math::BigFloat's internal representation of a zero as
4003 C<$m> is currently just a copy of the original number. The relation between
4004 C<$e> and C<$m> will stay always the same, though their real values might
4011 sub bint { Math::BigInt->new(shift); }
4013 $x = Math::BigInt->bstr("1234") # string "1234"
4014 $x = "$x"; # same as bstr()
4015 $x = Math::BigInt->bneg("1234"); # BigInt "-1234"
4016 $x = Math::BigInt->babs("-12345"); # BigInt "12345"
4017 $x = Math::BigInt->bnorm("-0.00"); # BigInt "0"
4018 $x = bint(1) + bint(2); # BigInt "3"
4019 $x = bint(1) + "2"; # ditto (auto-BigIntify of "2")
4020 $x = bint(1); # BigInt "1"
4021 $x = $x + 5 / 2; # BigInt "3"
4022 $x = $x ** 3; # BigInt "27"
4023 $x *= 2; # BigInt "54"
4024 $x = Math::BigInt->new(0); # BigInt "0"
4026 $x = Math::BigInt->badd(4,5) # BigInt "9"
4027 print $x->bsstr(); # 9e+0
4029 Examples for rounding:
4034 $x = Math::BigFloat->new(123.4567);
4035 $y = Math::BigFloat->new(123.456789);
4036 Math::BigFloat->accuracy(4); # no more A than 4
4038 ok ($x->copy()->fround(),123.4); # even rounding
4039 print $x->copy()->fround(),"\n"; # 123.4
4040 Math::BigFloat->round_mode('odd'); # round to odd
4041 print $x->copy()->fround(),"\n"; # 123.5
4042 Math::BigFloat->accuracy(5); # no more A than 5
4043 Math::BigFloat->round_mode('odd'); # round to odd
4044 print $x->copy()->fround(),"\n"; # 123.46
4045 $y = $x->copy()->fround(4),"\n"; # A = 4: 123.4
4046 print "$y, ",$y->accuracy(),"\n"; # 123.4, 4
4048 Math::BigFloat->accuracy(undef); # A not important now
4049 Math::BigFloat->precision(2); # P important
4050 print $x->copy()->bnorm(),"\n"; # 123.46
4051 print $x->copy()->fround(),"\n"; # 123.46
4053 Examples for converting:
4055 my $x = Math::BigInt->new('0b1'.'01' x 123);
4056 print "bin: ",$x->as_bin()," hex:",$x->as_hex()," dec: ",$x,"\n";
4058 =head1 Autocreating constants
4060 After C<use Math::BigInt ':constant'> all the B<integer> decimal, hexadecimal
4061 and binary constants in the given scope are converted to C<Math::BigInt>.
4062 This conversion happens at compile time.
4066 perl -MMath::BigInt=:constant -e 'print 2**100,"\n"'
4068 prints the integer value of C<2**100>. Note that without conversion of
4069 constants the expression 2**100 will be calculated as perl scalar.
4071 Please note that strings and floating point constants are not affected,
4074 use Math::BigInt qw/:constant/;
4076 $x = 1234567890123456789012345678901234567890
4077 + 123456789123456789;
4078 $y = '1234567890123456789012345678901234567890'
4079 + '123456789123456789';
4081 do not work. You need an explicit Math::BigInt->new() around one of the
4082 operands. You should also quote large constants to protect loss of precision:
4086 $x = Math::BigInt->new('1234567889123456789123456789123456789');
4088 Without the quotes Perl would convert the large number to a floating point
4089 constant at compile time and then hand the result to BigInt, which results in
4090 an truncated result or a NaN.
4092 This also applies to integers that look like floating point constants:
4094 use Math::BigInt ':constant';
4096 print ref(123e2),"\n";
4097 print ref(123.2e2),"\n";
4099 will print nothing but newlines. Use either L<bignum> or L<Math::BigFloat>
4100 to get this to work.
4104 Using the form $x += $y; etc over $x = $x + $y is faster, since a copy of $x
4105 must be made in the second case. For long numbers, the copy can eat up to 20%
4106 of the work (in the case of addition/subtraction, less for
4107 multiplication/division). If $y is very small compared to $x, the form
4108 $x += $y is MUCH faster than $x = $x + $y since making the copy of $x takes
4109 more time then the actual addition.
4111 With a technique called copy-on-write, the cost of copying with overload could
4112 be minimized or even completely avoided. A test implementation of COW did show
4113 performance gains for overloaded math, but introduced a performance loss due
4114 to a constant overhead for all other operations. So Math::BigInt does currently
4117 The rewritten version of this module (vs. v0.01) is slower on certain
4118 operations, like C<new()>, C<bstr()> and C<numify()>. The reason are that it
4119 does now more work and handles much more cases. The time spent in these
4120 operations is usually gained in the other math operations so that code on
4121 the average should get (much) faster. If they don't, please contact the author.
4123 Some operations may be slower for small numbers, but are significantly faster
4124 for big numbers. Other operations are now constant (O(1), like C<bneg()>,
4125 C<babs()> etc), instead of O(N) and thus nearly always take much less time.
4126 These optimizations were done on purpose.
4128 If you find the Calc module to slow, try to install any of the replacement
4129 modules and see if they help you.
4131 =head2 Alternative math libraries
4133 You can use an alternative library to drive Math::BigInt via:
4135 use Math::BigInt lib => 'Module';
4137 See L<MATH LIBRARY> for more information.
4139 For more benchmark results see L<http://bloodgate.com/perl/benchmarks.html>.
4143 =head1 Subclassing Math::BigInt
4145 The basic design of Math::BigInt allows simple subclasses with very little
4146 work, as long as a few simple rules are followed:
4152 The public API must remain consistent, i.e. if a sub-class is overloading
4153 addition, the sub-class must use the same name, in this case badd(). The
4154 reason for this is that Math::BigInt is optimized to call the object methods
4159 The private object hash keys like C<$x->{sign}> may not be changed, but
4160 additional keys can be added, like C<$x->{_custom}>.
4164 Accessor functions are available for all existing object hash keys and should
4165 be used instead of directly accessing the internal hash keys. The reason for
4166 this is that Math::BigInt itself has a pluggable interface which permits it
4167 to support different storage methods.
4171 More complex sub-classes may have to replicate more of the logic internal of
4172 Math::BigInt if they need to change more basic behaviors. A subclass that
4173 needs to merely change the output only needs to overload C<bstr()>.
4175 All other object methods and overloaded functions can be directly inherited
4176 from the parent class.
4178 At the very minimum, any subclass will need to provide it's own C<new()> and can
4179 store additional hash keys in the object. There are also some package globals
4180 that must be defined, e.g.:
4184 $precision = -2; # round to 2 decimal places
4185 $round_mode = 'even';
4188 Additionally, you might want to provide the following two globals to allow
4189 auto-upgrading and auto-downgrading to work correctly:
4194 This allows Math::BigInt to correctly retrieve package globals from the
4195 subclass, like C<$SubClass::precision>. See t/Math/BigInt/Subclass.pm or
4196 t/Math/BigFloat/SubClass.pm completely functional subclass examples.
4202 in your subclass to automatically inherit the overloading from the parent. If
4203 you like, you can change part of the overloading, look at Math::String for an
4208 When used like this:
4210 use Math::BigInt upgrade => 'Foo::Bar';
4212 certain operations will 'upgrade' their calculation and thus the result to
4213 the class Foo::Bar. Usually this is used in conjunction with Math::BigFloat:
4215 use Math::BigInt upgrade => 'Math::BigFloat';
4217 As a shortcut, you can use the module C<bignum>:
4221 Also good for oneliners:
4223 perl -Mbignum -le 'print 2 ** 255'
4225 This makes it possible to mix arguments of different classes (as in 2.5 + 2)
4226 as well es preserve accuracy (as in sqrt(3)).
4228 Beware: This feature is not fully implemented yet.
4232 The following methods upgrade themselves unconditionally; that is if upgrade
4233 is in effect, they will always hand up their work:
4245 Beware: This list is not complete.
4247 All other methods upgrade themselves only when one (or all) of their
4248 arguments are of the class mentioned in $upgrade (This might change in later
4249 versions to a more sophisticated scheme):
4255 =item broot() does not work
4257 The broot() function in BigInt may only work for small values. This will be
4258 fixed in a later version.
4260 =item Out of Memory!
4262 Under Perl prior to 5.6.0 having an C<use Math::BigInt ':constant';> and
4263 C<eval()> in your code will crash with "Out of memory". This is probably an
4264 overload/exporter bug. You can workaround by not having C<eval()>
4265 and ':constant' at the same time or upgrade your Perl to a newer version.
4267 =item Fails to load Calc on Perl prior 5.6.0
4269 Since eval(' use ...') can not be used in conjunction with ':constant', BigInt
4270 will fall back to eval { require ... } when loading the math lib on Perls
4271 prior to 5.6.0. This simple replaces '::' with '/' and thus might fail on
4272 filesystems using a different seperator.
4278 Some things might not work as you expect them. Below is documented what is
4279 known to be troublesome:
4283 =item bstr(), bsstr() and 'cmp'
4285 Both C<bstr()> and C<bsstr()> as well as automated stringify via overload now
4286 drop the leading '+'. The old code would return '+3', the new returns '3'.
4287 This is to be consistent with Perl and to make C<cmp> (especially with
4288 overloading) to work as you expect. It also solves problems with C<Test.pm>,
4289 because it's C<ok()> uses 'eq' internally.
4291 Mark Biggar said, when asked about to drop the '+' altogether, or make only
4294 I agree (with the first alternative), don't add the '+' on positive
4295 numbers. It's not as important anymore with the new internal
4296 form for numbers. It made doing things like abs and neg easier,
4297 but those have to be done differently now anyway.
4299 So, the following examples will now work all as expected:
4302 BEGIN { plan tests => 1 }
4305 my $x = new Math::BigInt 3*3;
4306 my $y = new Math::BigInt 3*3;
4309 print "$x eq 9" if $x eq $y;
4310 print "$x eq 9" if $x eq '9';
4311 print "$x eq 9" if $x eq 3*3;
4313 Additionally, the following still works:
4315 print "$x == 9" if $x == $y;
4316 print "$x == 9" if $x == 9;
4317 print "$x == 9" if $x == 3*3;
4319 There is now a C<bsstr()> method to get the string in scientific notation aka
4320 C<1e+2> instead of C<100>. Be advised that overloaded 'eq' always uses bstr()
4321 for comparison, but Perl will represent some numbers as 100 and others
4322 as 1e+308. If in doubt, convert both arguments to Math::BigInt before
4323 comparing them as strings:
4326 BEGIN { plan tests => 3 }
4329 $x = Math::BigInt->new('1e56'); $y = 1e56;
4330 ok ($x,$y); # will fail
4331 ok ($x->bsstr(),$y); # okay
4332 $y = Math::BigInt->new($y);
4335 Alternatively, simple use C<< <=> >> for comparisons, this will get it
4336 always right. There is not yet a way to get a number automatically represented
4337 as a string that matches exactly the way Perl represents it.
4339 See also the section about L<Infinity and Not a Number> for problems in
4344 C<int()> will return (at least for Perl v5.7.1 and up) another BigInt, not a
4347 $x = Math::BigInt->new(123);
4348 $y = int($x); # BigInt 123
4349 $x = Math::BigFloat->new(123.45);
4350 $y = int($x); # BigInt 123
4352 In all Perl versions you can use C<as_number()> or C<as_int> for the same
4355 $x = Math::BigFloat->new(123.45);
4356 $y = $x->as_number(); # BigInt 123
4357 $y = $x->as_int(); # ditto
4359 This also works for other subclasses, like Math::String.
4361 If you want a real Perl scalar, use C<numify()>:
4363 $y = $x->numify(); # 123 as scalar
4365 This is seldom necessary, though, because this is done automatically, like
4366 when you access an array:
4368 $z = $array[$x]; # does work automatically
4372 The following will probably not do what you expect:
4374 $c = Math::BigInt->new(123);
4375 print $c->length(),"\n"; # prints 30
4377 It prints both the number of digits in the number and in the fraction part
4378 since print calls C<length()> in list context. Use something like:
4380 print scalar $c->length(),"\n"; # prints 3
4384 The following will probably not do what you expect:
4386 print $c->bdiv(10000),"\n";
4388 It prints both quotient and remainder since print calls C<bdiv()> in list
4389 context. Also, C<bdiv()> will modify $c, so be careful. You probably want
4392 print $c / 10000,"\n";
4393 print scalar $c->bdiv(10000),"\n"; # or if you want to modify $c
4397 The quotient is always the greatest integer less than or equal to the
4398 real-valued quotient of the two operands, and the remainder (when it is
4399 nonzero) always has the same sign as the second operand; so, for
4409 As a consequence, the behavior of the operator % agrees with the
4410 behavior of Perl's built-in % operator (as documented in the perlop
4411 manpage), and the equation
4413 $x == ($x / $y) * $y + ($x % $y)
4415 holds true for any $x and $y, which justifies calling the two return
4416 values of bdiv() the quotient and remainder. The only exception to this rule
4417 are when $y == 0 and $x is negative, then the remainder will also be
4418 negative. See below under "infinity handling" for the reasoning behind this.
4420 Perl's 'use integer;' changes the behaviour of % and / for scalars, but will
4421 not change BigInt's way to do things. This is because under 'use integer' Perl
4422 will do what the underlying C thinks is right and this is different for each
4423 system. If you need BigInt's behaving exactly like Perl's 'use integer', bug
4424 the author to implement it ;)
4426 =item infinity handling
4428 Here are some examples that explain the reasons why certain results occur while
4431 The following table shows the result of the division and the remainder, so that
4432 the equation above holds true. Some "ordinary" cases are strewn in to show more
4433 clearly the reasoning:
4435 A / B = C, R so that C * B + R = A
4436 =========================================================
4437 5 / 8 = 0, 5 0 * 8 + 5 = 5
4438 0 / 8 = 0, 0 0 * 8 + 0 = 0
4439 0 / inf = 0, 0 0 * inf + 0 = 0
4440 0 /-inf = 0, 0 0 * -inf + 0 = 0
4441 5 / inf = 0, 5 0 * inf + 5 = 5
4442 5 /-inf = 0, 5 0 * -inf + 5 = 5
4443 -5/ inf = 0, -5 0 * inf + -5 = -5
4444 -5/-inf = 0, -5 0 * -inf + -5 = -5
4445 inf/ 5 = inf, 0 inf * 5 + 0 = inf
4446 -inf/ 5 = -inf, 0 -inf * 5 + 0 = -inf
4447 inf/ -5 = -inf, 0 -inf * -5 + 0 = inf
4448 -inf/ -5 = inf, 0 inf * -5 + 0 = -inf
4449 5/ 5 = 1, 0 1 * 5 + 0 = 5
4450 -5/ -5 = 1, 0 1 * -5 + 0 = -5
4451 inf/ inf = 1, 0 1 * inf + 0 = inf
4452 -inf/-inf = 1, 0 1 * -inf + 0 = -inf
4453 inf/-inf = -1, 0 -1 * -inf + 0 = inf
4454 -inf/ inf = -1, 0 1 * -inf + 0 = -inf
4455 8/ 0 = inf, 8 inf * 0 + 8 = 8
4456 inf/ 0 = inf, inf inf * 0 + inf = inf
4459 These cases below violate the "remainder has the sign of the second of the two
4460 arguments", since they wouldn't match up otherwise.
4462 A / B = C, R so that C * B + R = A
4463 ========================================================
4464 -inf/ 0 = -inf, -inf -inf * 0 + inf = -inf
4465 -8/ 0 = -inf, -8 -inf * 0 + 8 = -8
4467 =item Modifying and =
4471 $x = Math::BigFloat->new(5);
4474 It will not do what you think, e.g. making a copy of $x. Instead it just makes
4475 a second reference to the B<same> object and stores it in $y. Thus anything
4476 that modifies $x (except overloaded operators) will modify $y, and vice versa.
4477 Or in other words, C<=> is only safe if you modify your BigInts only via
4478 overloaded math. As soon as you use a method call it breaks:
4481 print "$x, $y\n"; # prints '10, 10'
4483 If you want a true copy of $x, use:
4487 You can also chain the calls like this, this will make first a copy and then
4490 $y = $x->copy()->bmul(2);
4492 See also the documentation for overload.pm regarding C<=>.
4496 C<bpow()> (and the rounding functions) now modifies the first argument and
4497 returns it, unlike the old code which left it alone and only returned the
4498 result. This is to be consistent with C<badd()> etc. The first three will
4499 modify $x, the last one won't:
4501 print bpow($x,$i),"\n"; # modify $x
4502 print $x->bpow($i),"\n"; # ditto
4503 print $x **= $i,"\n"; # the same
4504 print $x ** $i,"\n"; # leave $x alone
4506 The form C<$x **= $y> is faster than C<$x = $x ** $y;>, though.
4508 =item Overloading -$x
4518 since overload calls C<sub($x,0,1);> instead of C<neg($x)>. The first variant
4519 needs to preserve $x since it does not know that it later will get overwritten.
4520 This makes a copy of $x and takes O(N), but $x->bneg() is O(1).
4522 =item Mixing different object types
4524 In Perl you will get a floating point value if you do one of the following:
4530 With overloaded math, only the first two variants will result in a BigFloat:
4535 $mbf = Math::BigFloat->new(5);
4536 $mbi2 = Math::BigInteger->new(5);
4537 $mbi = Math::BigInteger->new(2);
4539 # what actually gets called:
4540 $float = $mbf + $mbi; # $mbf->badd()
4541 $float = $mbf / $mbi; # $mbf->bdiv()
4542 $integer = $mbi + $mbf; # $mbi->badd()
4543 $integer = $mbi2 / $mbi; # $mbi2->bdiv()
4544 $integer = $mbi2 / $mbf; # $mbi2->bdiv()
4546 This is because math with overloaded operators follows the first (dominating)
4547 operand, and the operation of that is called and returns thus the result. So,
4548 Math::BigInt::bdiv() will always return a Math::BigInt, regardless whether
4549 the result should be a Math::BigFloat or the second operant is one.
4551 To get a Math::BigFloat you either need to call the operation manually,
4552 make sure the operands are already of the proper type or casted to that type
4553 via Math::BigFloat->new():
4555 $float = Math::BigFloat->new($mbi2) / $mbi; # = 2.5
4557 Beware of simple "casting" the entire expression, this would only convert
4558 the already computed result:
4560 $float = Math::BigFloat->new($mbi2 / $mbi); # = 2.0 thus wrong!
4562 Beware also of the order of more complicated expressions like:
4564 $integer = ($mbi2 + $mbi) / $mbf; # int / float => int
4565 $integer = $mbi2 / Math::BigFloat->new($mbi); # ditto
4567 If in doubt, break the expression into simpler terms, or cast all operands
4568 to the desired resulting type.
4570 Scalar values are a bit different, since:
4575 will both result in the proper type due to the way the overloaded math works.
4577 This section also applies to other overloaded math packages, like Math::String.
4579 One solution to you problem might be autoupgrading|upgrading. See the
4580 pragmas L<bignum>, L<bigint> and L<bigrat> for an easy way to do this.
4584 C<bsqrt()> works only good if the result is a big integer, e.g. the square
4585 root of 144 is 12, but from 12 the square root is 3, regardless of rounding
4586 mode. The reason is that the result is always truncated to an integer.
4588 If you want a better approximation of the square root, then use:
4590 $x = Math::BigFloat->new(12);
4591 Math::BigFloat->precision(0);
4592 Math::BigFloat->round_mode('even');
4593 print $x->copy->bsqrt(),"\n"; # 4
4595 Math::BigFloat->precision(2);
4596 print $x->bsqrt(),"\n"; # 3.46
4597 print $x->bsqrt(3),"\n"; # 3.464
4601 For negative numbers in base see also L<brsft|brsft>.
4607 This program is free software; you may redistribute it and/or modify it under
4608 the same terms as Perl itself.
4612 L<Math::BigFloat>, L<Math::BigRat> and L<Math::Big> as well as
4613 L<Math::BigInt::BitVect>, L<Math::BigInt::Pari> and L<Math::BigInt::GMP>.
4615 The pragmas L<bignum>, L<bigint> and L<bigrat> also might be of interest
4616 because they solve the autoupgrading/downgrading issue, at least partly.
4619 L<http://search.cpan.org/search?mode=module&query=Math%3A%3ABigInt> contains
4620 more documentation including a full version history, testcases, empty
4621 subclass files and benchmarks.
4625 Original code by Mark Biggar, overloaded interface by Ilya Zakharevich.
4626 Completely rewritten by Tels http://bloodgate.com in late 2000, 2001 - 2006
4627 and still at it in 2007.
4629 Many people contributed in one or more ways to the final beast, see the file
4630 CREDITS for an (incomplete) list. If you miss your name, please drop me a