Commit | Line | Data |
58cde26e |
1 | #!/usr/bin/perl -w |
2 | |
58cde26e |
3 | # The following hash values are internally used: |
4 | # _e: exponent (BigInt) |
5 | # _m: mantissa (absolute BigInt) |
6 | # sign: +,-,"NaN" if not a number |
7 | # _a: accuracy |
8 | # _p: precision |
0716bf9b |
9 | # _f: flags, used to signal MBI not to touch our private parts |
58cde26e |
10 | # _cow: Copy-On-Write (NRY) |
11 | |
a0d0e21e |
12 | package Math::BigFloat; |
13 | |
574bacfe |
14 | $VERSION = '1.20'; |
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15 | require 5.005; |
16 | use Exporter; |
0716bf9b |
17 | use Math::BigInt qw/objectify/; |
58cde26e |
18 | @ISA = qw( Exporter Math::BigInt); |
19 | # can not export bneg/babs since the are only in MBI |
20 | @EXPORT_OK = qw( |
21 | bcmp |
22 | badd bmul bdiv bmod bnorm bsub |
23 | bgcd blcm bround bfround |
24 | bpow bnan bzero bfloor bceil |
574bacfe |
25 | bacmp bstr binc bdec binf |
0716bf9b |
26 | is_odd is_even is_nan is_inf is_positive is_negative |
58cde26e |
27 | is_zero is_one sign |
28 | ); |
a0d0e21e |
29 | |
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30 | #@EXPORT = qw( ); |
31 | use strict; |
32 | use vars qw/$AUTOLOAD $accuracy $precision $div_scale $rnd_mode/; |
33 | my $class = "Math::BigFloat"; |
a0d0e21e |
34 | |
a5f75d66 |
35 | use overload |
58cde26e |
36 | '<=>' => sub { |
37 | $_[2] ? |
38 | $class->bcmp($_[1],$_[0]) : |
39 | $class->bcmp($_[0],$_[1])}, |
0716bf9b |
40 | 'int' => sub { $_[0]->as_number() }, # 'trunc' to bigint |
a5f75d66 |
41 | ; |
a0d0e21e |
42 | |
0716bf9b |
43 | ############################################################################## |
44 | # global constants, flags and accessory |
45 | |
46 | use constant MB_NEVER_ROUND => 0x0001; |
47 | |
58cde26e |
48 | # are NaNs ok? |
49 | my $NaNOK=1; |
58cde26e |
50 | # constant for easier life |
51 | my $nan = 'NaN'; |
58cde26e |
52 | |
53 | # Rounding modes one of 'even', 'odd', '+inf', '-inf', 'zero' or 'trunc' |
54 | $rnd_mode = 'even'; |
55 | $accuracy = undef; |
56 | $precision = undef; |
57 | $div_scale = 40; |
58 | |
574bacfe |
59 | # in case we call SUPER::->foo() and this wants to call modify() |
60 | # sub modify () { 0; } |
61 | |
58cde26e |
62 | { |
63 | # checks for AUTOLOAD |
64 | my %methods = map { $_ => 1 } |
65 | qw / fadd fsub fmul fdiv fround ffround fsqrt fmod fstr fsstr fpow fnorm |
66 | fabs fneg fint fcmp fzero fnan finc fdec |
67 | /; |
68 | |
69 | sub method_valid { return exists $methods{$_[0]||''}; } |
a0d0e21e |
70 | } |
0e8b9368 |
71 | |
58cde26e |
72 | ############################################################################## |
73 | # constructors |
a0d0e21e |
74 | |
58cde26e |
75 | sub new |
76 | { |
77 | # create a new BigFloat object from a string or another bigfloat object. |
78 | # _e: exponent |
79 | # _m: mantissa |
80 | # sign => sign (+/-), or "NaN" |
a0d0e21e |
81 | |
58cde26e |
82 | my $class = shift; |
83 | |
84 | my $wanted = shift; # avoid numify call by not using || here |
85 | return $class->bzero() if !defined $wanted; # default to 0 |
86 | return $wanted->copy() if ref($wanted) eq $class; |
a0d0e21e |
87 | |
58cde26e |
88 | my $round = shift; $round = 0 if !defined $round; # no rounding as default |
89 | my $self = {}; bless $self, $class; |
b22b3e31 |
90 | # shortcut for bigints and its subclasses |
0716bf9b |
91 | if ((ref($wanted)) && (ref($wanted) ne $class)) |
58cde26e |
92 | { |
0716bf9b |
93 | $self->{_m} = $wanted->as_number(); # get us a bigint copy |
58cde26e |
94 | $self->{_e} = Math::BigInt->new(0); |
95 | $self->{_m}->babs(); |
96 | $self->{sign} = $wanted->sign(); |
0716bf9b |
97 | return $self->bnorm(); |
58cde26e |
98 | } |
99 | # got string |
100 | # handle '+inf', '-inf' first |
101 | if ($wanted =~ /^[+-]inf$/) |
102 | { |
103 | $self->{_e} = Math::BigInt->new(0); |
104 | $self->{_m} = Math::BigInt->new(0); |
105 | $self->{sign} = $wanted; |
0716bf9b |
106 | return $self->bnorm(); |
58cde26e |
107 | } |
108 | #print "new string '$wanted'\n"; |
109 | my ($mis,$miv,$mfv,$es,$ev) = Math::BigInt::_split(\$wanted); |
110 | if (!ref $mis) |
111 | { |
112 | die "$wanted is not a number initialized to $class" if !$NaNOK; |
113 | $self->{_e} = Math::BigInt->new(0); |
114 | $self->{_m} = Math::BigInt->new(0); |
115 | $self->{sign} = $nan; |
116 | } |
117 | else |
118 | { |
119 | # make integer from mantissa by adjusting exp, then convert to bigint |
120 | $self->{_e} = Math::BigInt->new("$$es$$ev"); # exponent |
121 | $self->{_m} = Math::BigInt->new("$$mis$$miv$$mfv"); # create mantissa |
122 | # 3.123E0 = 3123E-3, and 3.123E-2 => 3123E-5 |
123 | $self->{_e} -= CORE::length($$mfv); |
124 | $self->{sign} = $self->{_m}->sign(); $self->{_m}->babs(); |
125 | } |
0716bf9b |
126 | #print "$wanted => $self->{sign} $self->{value}\n"; |
58cde26e |
127 | $self->bnorm(); # first normalize |
128 | # if any of the globals is set, round to them and thus store them insid $self |
129 | $self->round($accuracy,$precision,$rnd_mode) |
130 | if defined $accuracy || defined $precision; |
131 | return $self; |
132 | } |
a0d0e21e |
133 | |
58cde26e |
134 | sub bnan |
135 | { |
136 | # create a bigfloat 'NaN', if given a BigFloat, set it to 'NaN' |
137 | my $self = shift; |
138 | $self = $class if !defined $self; |
139 | if (!ref($self)) |
288d023a |
140 | { |
58cde26e |
141 | my $c = $self; $self = {}; bless $self, $c; |
a0d0e21e |
142 | } |
574bacfe |
143 | $self->{_m} = Math::BigInt->bzero(); |
144 | $self->{_e} = Math::BigInt->bzero(); |
58cde26e |
145 | $self->{sign} = $nan; |
58cde26e |
146 | return $self; |
147 | } |
a0d0e21e |
148 | |
58cde26e |
149 | sub binf |
150 | { |
151 | # create a bigfloat '+-inf', if given a BigFloat, set it to '+-inf' |
152 | my $self = shift; |
153 | my $sign = shift; $sign = '+' if !defined $sign || $sign ne '-'; |
a0d0e21e |
154 | |
58cde26e |
155 | $self = $class if !defined $self; |
156 | if (!ref($self)) |
157 | { |
158 | my $c = $self; $self = {}; bless $self, $c; |
159 | } |
574bacfe |
160 | $self->{_m} = Math::BigInt->bzero(); |
161 | $self->{_e} = Math::BigInt->bzero(); |
58cde26e |
162 | $self->{sign} = $sign.'inf'; |
58cde26e |
163 | return $self; |
164 | } |
a0d0e21e |
165 | |
574bacfe |
166 | sub bone |
167 | { |
168 | # create a bigfloat '+-1', if given a BigFloat, set it to '+-1' |
169 | my $self = shift; |
170 | my $sign = shift; $sign = '+' if !defined $sign || $sign ne '-'; |
171 | |
172 | $self = $class if !defined $self; |
173 | if (!ref($self)) |
174 | { |
175 | my $c = $self; $self = {}; bless $self, $c; |
176 | } |
177 | $self->{_m} = Math::BigInt->bone(); |
178 | $self->{_e} = Math::BigInt->bzero(); |
179 | $self->{sign} = $sign; |
180 | return $self; |
181 | } |
182 | |
58cde26e |
183 | sub bzero |
184 | { |
185 | # create a bigfloat '+0', if given a BigFloat, set it to 0 |
186 | my $self = shift; |
187 | $self = $class if !defined $self; |
188 | if (!ref($self)) |
189 | { |
190 | my $c = $self; $self = {}; bless $self, $c; |
191 | } |
574bacfe |
192 | $self->{_m} = Math::BigInt->bzero(); |
193 | $self->{_e} = Math::BigInt->bone(); |
58cde26e |
194 | $self->{sign} = '+'; |
58cde26e |
195 | return $self; |
196 | } |
197 | |
198 | ############################################################################## |
199 | # string conversation |
200 | |
201 | sub bstr |
202 | { |
203 | # (ref to BFLOAT or num_str ) return num_str |
204 | # Convert number from internal format to (non-scientific) string format. |
205 | # internal format is always normalized (no leading zeros, "-0" => "+0") |
58cde26e |
206 | my ($self,$x) = objectify(1,@_); |
207 | |
574bacfe |
208 | #die "Oups! e was $nan" if $x->{_e}->{sign} eq $nan; |
209 | #die "Oups! m was $nan" if $x->{_m}->{sign} eq $nan; |
210 | if ($x->{sign} !~ /^[+-]$/) |
58cde26e |
211 | { |
574bacfe |
212 | return $x->{sign} unless $x->{sign} eq '+inf'; # -inf, NaN |
213 | return 'inf'; # +inf |
58cde26e |
214 | } |
215 | |
574bacfe |
216 | my $es = '0'; my $len = 1; my $cad = 0; my $dot = '.'; |
217 | |
218 | my $not_zero = !$x->is_zero(); |
219 | if ($not_zero) |
58cde26e |
220 | { |
574bacfe |
221 | $es = $x->{_m}->bstr(); |
222 | $len = CORE::length($es); |
223 | if (!$x->{_e}->is_zero()) |
224 | # { |
225 | # $es = $x->{sign}.$es if $x->{sign} eq '-'; |
226 | # } |
227 | # else |
58cde26e |
228 | { |
574bacfe |
229 | if ($x->{_e}->sign() eq '-') |
230 | { |
231 | $dot = ''; |
232 | if ($x->{_e} <= -$len) |
233 | { |
234 | # print "style: 0.xxxx\n"; |
235 | my $r = $x->{_e}->copy(); $r->babs()->bsub( CORE::length($es) ); |
236 | $es = '0.'. ('0' x $r) . $es; $cad = -($len+$r); |
237 | } |
238 | else |
239 | { |
240 | # print "insert '.' at $x->{_e} in '$es'\n"; |
241 | substr($es,$x->{_e},0) = '.'; $cad = $x->{_e}; |
242 | } |
243 | } |
244 | else |
245 | { |
246 | # expand with zeros |
247 | $es .= '0' x $x->{_e}; $len += $x->{_e}; $cad = 0; |
248 | } |
82cf049f |
249 | } |
574bacfe |
250 | } # if not zero |
251 | $es = $x->{sign}.$es if $x->{sign} eq '-'; |
252 | # if set accuracy or precision, pad with zeros |
253 | if ((defined $x->{_a}) && ($not_zero)) |
254 | { |
255 | # 123400 => 6, 0.1234 => 4, 0.001234 => 4 |
256 | my $zeros = $x->{_a} - $cad; # cad == 0 => 12340 |
257 | $zeros = $x->{_a} - $len if $cad != $len; |
258 | #print "acc padd $x->{_a} $zeros (len $len cad $cad)\n"; |
259 | $es .= $dot.'0' x $zeros if $zeros > 0; |
82cf049f |
260 | } |
574bacfe |
261 | elsif ($x->{_p} || 0 < 0) |
58cde26e |
262 | { |
574bacfe |
263 | # 123400 => 6, 0.1234 => 4, 0.001234 => 6 |
264 | my $zeros = -$x->{_p} + $cad; |
265 | #print "pre padd $x->{_p} $zeros (len $len cad $cad)\n"; |
266 | $es .= $dot.'0' x $zeros if $zeros > 0; |
58cde26e |
267 | } |
58cde26e |
268 | return $es; |
82cf049f |
269 | } |
f216259d |
270 | |
58cde26e |
271 | sub bsstr |
272 | { |
273 | # (ref to BFLOAT or num_str ) return num_str |
274 | # Convert number from internal format to scientific string format. |
275 | # internal format is always normalized (no leading zeros, "-0E0" => "+0E0") |
58cde26e |
276 | my ($self,$x) = objectify(1,@_); |
a0d0e21e |
277 | |
574bacfe |
278 | #die "Oups! e was $nan" if $x->{_e}->{sign} eq $nan; |
279 | #die "Oups! m was $nan" if $x->{_m}->{sign} eq $nan; |
280 | if ($x->{sign} !~ /^[+-]$/) |
281 | { |
282 | return $x->{sign} unless $x->{sign} eq '+inf'; # -inf, NaN |
283 | return 'inf'; # +inf |
284 | } |
58cde26e |
285 | my $sign = $x->{_e}->{sign}; $sign = '' if $sign eq '-'; |
286 | my $sep = 'e'.$sign; |
287 | return $x->{_m}->bstr().$sep.$x->{_e}->bstr(); |
288 | } |
289 | |
290 | sub numify |
291 | { |
292 | # Make a number from a BigFloat object |
574bacfe |
293 | # simple return string and let Perl's atoi()/atof() handle the rest |
58cde26e |
294 | my ($self,$x) = objectify(1,@_); |
295 | return $x->bsstr(); |
296 | } |
a0d0e21e |
297 | |
58cde26e |
298 | ############################################################################## |
299 | # public stuff (usually prefixed with "b") |
300 | |
301 | # really? Just for exporting them is not what I had in mind |
302 | #sub babs |
303 | # { |
304 | # $class->SUPER::babs($class,@_); |
305 | # } |
306 | #sub bneg |
307 | # { |
308 | # $class->SUPER::bneg($class,@_); |
309 | # } |
574bacfe |
310 | |
311 | # tels 2001-08-04 |
312 | # todo: this must be overwritten and return NaN for non-integer values |
313 | # band(), bior(), bxor(), too |
58cde26e |
314 | #sub bnot |
315 | # { |
316 | # $class->SUPER::bnot($class,@_); |
317 | # } |
318 | |
319 | sub bcmp |
320 | { |
321 | # Compares 2 values. Returns one of undef, <0, =0, >0. (suitable for sort) |
322 | # (BFLOAT or num_str, BFLOAT or num_str) return cond_code |
323 | my ($self,$x,$y) = objectify(2,@_); |
58cde26e |
324 | |
0716bf9b |
325 | if (($x->{sign} !~ /^[+-]$/) || ($y->{sign} !~ /^[+-]$/)) |
326 | { |
327 | # handle +-inf and NaN |
328 | return undef if (($x->{sign} eq $nan) || ($y->{sign} eq $nan)); |
329 | return 0 if ($x->{sign} eq $y->{sign}) && ($x->{sign} =~ /^[+-]inf$/); |
330 | return +1 if $x->{sign} eq '+inf'; |
331 | return -1 if $x->{sign} eq '-inf'; |
332 | return -1 if $y->{sign} eq '+inf'; |
333 | return +1 if $y->{sign} eq '-inf'; |
334 | } |
335 | |
336 | # check sign for speed first |
574bacfe |
337 | return 1 if $x->{sign} eq '+' && $y->{sign} eq '-'; # does also 0 <=> -y |
58cde26e |
338 | return -1 if $x->{sign} eq '-' && $y->{sign} eq '+'; # does also -x <=> 0 |
339 | |
574bacfe |
340 | # shortcut |
341 | my $xz = $x->is_zero(); |
342 | my $yz = $y->is_zero(); |
343 | return 0 if $xz && $yz; # 0 <=> 0 |
344 | return -1 if $xz && $y->{sign} eq '+'; # 0 <=> +y |
345 | return 1 if $yz && $x->{sign} eq '+'; # +x <=> 0 |
58cde26e |
346 | |
347 | # adjust so that exponents are equal |
348 | my $lx = $x->{_m}->length() + $x->{_e}; |
349 | my $ly = $y->{_m}->length() + $y->{_e}; |
350 | # print "x $x y $y lx $lx ly $ly\n"; |
351 | my $l = $lx - $ly; $l = -$l if $x->{sign} eq '-'; |
352 | # print "$l $x->{sign}\n"; |
353 | return $l if $l != 0; |
354 | |
0716bf9b |
355 | # lengths are equal, so compare mantissa, if equal, compare exponents |
b22b3e31 |
356 | # this assumes normalized numbers (no trailing zeros etc!) |
58cde26e |
357 | my $rc = $x->{_m} <=> $y->{_m} || $x->{_e} <=> $y->{_e}; |
358 | $rc = -$rc if $x->{sign} eq '-'; # -124 < -123 |
359 | return $rc; |
360 | } |
361 | |
362 | sub bacmp |
363 | { |
364 | # Compares 2 values, ignoring their signs. |
365 | # Returns one of undef, <0, =0, >0. (suitable for sort) |
366 | # (BFLOAT or num_str, BFLOAT or num_str) return cond_code |
367 | my ($self,$x,$y) = objectify(2,@_); |
368 | return undef if (($x->{sign} eq $nan) || ($y->{sign} eq $nan)); |
369 | |
370 | # signs are ignored, so check length |
371 | # length(x) is length(m)+e aka length of non-fraction part |
372 | # the longer one is bigger |
373 | my $l = $x->length() - $y->length(); |
374 | #print "$l\n"; |
375 | return $l if $l != 0; |
376 | #print "equal lengths\n"; |
377 | |
378 | # if both are equal long, make full compare |
379 | # first compare only the mantissa |
380 | # if mantissa are equal, compare fractions |
381 | |
382 | return $x->{_m} <=> $y->{_m} || $x->{_e} <=> $y->{_e}; |
383 | } |
a0d0e21e |
384 | |
58cde26e |
385 | sub badd |
386 | { |
387 | # add second arg (BFLOAT or string) to first (BFLOAT) (modifies first) |
388 | # return result as BFLOAT |
58cde26e |
389 | my ($self,$x,$y,$a,$p,$r) = objectify(2,@_); |
390 | |
574bacfe |
391 | # inf and NaN handling |
392 | if (($x->{sign} !~ /^[+-]$/) || ($y->{sign} !~ /^[+-]$/)) |
393 | { |
394 | # NaN first |
395 | return $x->bnan() if (($x->{sign} eq $nan) || ($y->{sign} eq $nan)); |
396 | # inf handline |
397 | if (($x->{sign} =~ /^[+-]inf$/) && ($y->{sign} =~ /^[+-]inf$/)) |
398 | { |
399 | # + and + => +, - and - => -, + and - => 0, - and + => 0 |
400 | return $x->bzero() if $x->{sign} ne $y->{sign}; |
401 | return $x; |
402 | } |
403 | # +-inf + something => +inf |
404 | # something +-inf => +-inf |
405 | $x->{sign} = $y->{sign}, return $x if $y->{sign} =~ /^[+-]inf$/; |
406 | return $x; |
407 | } |
408 | |
58cde26e |
409 | # speed: no add for 0+y or x+0 |
410 | return $x if $y->is_zero(); # x+0 |
411 | if ($x->is_zero()) # 0+y |
412 | { |
413 | # make copy, clobbering up x (modify in place!) |
414 | $x->{_e} = $y->{_e}->copy(); |
415 | $x->{_m} = $y->{_m}->copy(); |
416 | $x->{sign} = $y->{sign} || $nan; |
417 | return $x->round($a,$p,$r,$y); |
a0d0e21e |
418 | } |
58cde26e |
419 | |
420 | # take lower of the two e's and adapt m1 to it to match m2 |
421 | my $e = $y->{_e}; $e = Math::BigInt::bzero() if !defined $e; # if no BFLOAT |
422 | $e = $e - $x->{_e}; |
423 | my $add = $y->{_m}->copy(); |
424 | if ($e < 0) |
425 | { |
0716bf9b |
426 | # print "e < 0\n"; |
58cde26e |
427 | #print "\$x->{_m}: $x->{_m} "; |
428 | #print "\$x->{_e}: $x->{_e}\n"; |
429 | my $e1 = $e->copy()->babs(); |
430 | $x->{_m} *= (10 ** $e1); |
431 | $x->{_e} += $e; # need the sign of e |
432 | #$x->{_m} += $y->{_m}; |
433 | #print "\$x->{_m}: $x->{_m} "; |
434 | #print "\$x->{_e}: $x->{_e}\n"; |
435 | } |
436 | elsif ($e > 0) |
437 | { |
0716bf9b |
438 | # print "e > 0\n"; |
58cde26e |
439 | #print "\$x->{_m}: $x->{_m} \$y->{_m}: $y->{_m} \$e: $e ",ref($e),"\n"; |
440 | $add *= (10 ** $e); |
441 | #$x->{_m} += $y->{_m} * (10 ** $e); |
442 | #print "\$x->{_m}: $x->{_m}\n"; |
443 | } |
444 | # else: both e are same, so leave them |
445 | #print "badd $x->{sign}$x->{_m} + $y->{sign}$add\n"; |
446 | # fiddle with signs |
447 | $x->{_m}->{sign} = $x->{sign}; |
448 | $add->{sign} = $y->{sign}; |
449 | # finally do add/sub |
450 | $x->{_m} += $add; |
451 | # re-adjust signs |
452 | $x->{sign} = $x->{_m}->{sign}; |
453 | $x->{_m}->{sign} = '+'; |
0716bf9b |
454 | #$x->bnorm(); # delete trailing zeros |
58cde26e |
455 | return $x->round($a,$p,$r,$y); |
456 | } |
457 | |
458 | sub bsub |
459 | { |
0716bf9b |
460 | # (BigFloat or num_str, BigFloat or num_str) return BigFloat |
58cde26e |
461 | # subtract second arg from first, modify first |
462 | my ($self,$x,$y) = objectify(2,@_); |
a0d0e21e |
463 | |
58cde26e |
464 | $x->badd($y->bneg()); # badd does not leave internal zeros |
465 | $y->bneg(); # refix y, assumes no one reads $y in between |
0716bf9b |
466 | return $x; # badd() already normalized and rounded |
58cde26e |
467 | } |
468 | |
469 | sub binc |
470 | { |
471 | # increment arg by one |
472 | my ($self,$x,$a,$p,$r) = objectify(1,@_); |
58cde26e |
473 | $x->badd($self->_one())->round($a,$p,$r); |
474 | } |
475 | |
476 | sub bdec |
477 | { |
478 | # decrement arg by one |
479 | my ($self,$x,$a,$p,$r) = objectify(1,@_); |
58cde26e |
480 | $x->badd($self->_one('-'))->round($a,$p,$r); |
481 | } |
482 | |
483 | sub blcm |
484 | { |
485 | # (BINT or num_str, BINT or num_str) return BINT |
486 | # does not modify arguments, but returns new object |
487 | # Lowest Common Multiplicator |
58cde26e |
488 | |
489 | my ($self,@arg) = objectify(0,@_); |
490 | my $x = $self->new(shift @arg); |
491 | while (@arg) { $x = _lcm($x,shift @arg); } |
492 | $x; |
493 | } |
494 | |
495 | sub bgcd |
496 | { |
497 | # (BINT or num_str, BINT or num_str) return BINT |
498 | # does not modify arguments, but returns new object |
499 | # GCD -- Euclids algorithm Knuth Vol 2 pg 296 |
58cde26e |
500 | |
501 | my ($self,@arg) = objectify(0,@_); |
502 | my $x = $self->new(shift @arg); |
503 | while (@arg) { $x = _gcd($x,shift @arg); } |
504 | $x; |
505 | } |
506 | |
507 | sub is_zero |
508 | { |
509 | # return true if arg (BINT or num_str) is zero (array '+', '0') |
510 | my $x = shift; $x = $class->new($x) unless ref $x; |
574bacfe |
511 | |
512 | return 1 if $x->{sign} eq '+' && $x->{_m}->is_zero(); |
513 | return 0; |
58cde26e |
514 | } |
515 | |
516 | sub is_one |
517 | { |
518 | # return true if arg (BINT or num_str) is +1 (array '+', '1') |
519 | # or -1 if signis given |
520 | my $x = shift; $x = $class->new($x) unless ref $x; |
521 | #my ($self,$x) = objectify(1,@_); |
522 | my $sign = $_[2] || '+'; |
523 | return ($x->{sign} eq $sign && $x->{_e}->is_zero() && $x->{_m}->is_one()); |
524 | } |
525 | |
526 | sub is_odd |
527 | { |
b22b3e31 |
528 | # return true if arg (BINT or num_str) is odd or false if even |
58cde26e |
529 | my $x = shift; $x = $class->new($x) unless ref $x; |
530 | #my ($self,$x) = objectify(1,@_); |
0716bf9b |
531 | |
532 | return 0 if $x->{sign} !~ /^[+-]$/; # NaN & +-inf aren't |
533 | return ($x->{_e}->is_zero() && $x->{_m}->is_odd()); |
58cde26e |
534 | } |
535 | |
536 | sub is_even |
537 | { |
b22b3e31 |
538 | # return true if arg (BINT or num_str) is even or false if odd |
58cde26e |
539 | my $x = shift; $x = $class->new($x) unless ref $x; |
540 | #my ($self,$x) = objectify(1,@_); |
0716bf9b |
541 | |
542 | return 0 if $x->{sign} !~ /^[+-]$/; # NaN & +-inf aren't |
543 | return 1 if $x->{_m}->is_zero(); # 0e1 is even |
544 | return ($x->{_e}->is_zero() && $x->{_m}->is_even()); # 123.45 is never |
58cde26e |
545 | } |
546 | |
547 | sub bmul |
548 | { |
549 | # multiply two numbers -- stolen from Knuth Vol 2 pg 233 |
550 | # (BINT or num_str, BINT or num_str) return BINT |
551 | my ($self,$x,$y,$a,$p,$r) = objectify(2,@_); |
58cde26e |
552 | |
0716bf9b |
553 | # print "mbf bmul $x->{_m}e$x->{_e} $y->{_m}e$y->{_e}\n"; |
58cde26e |
554 | return $x->bnan() if (($x->{sign} eq $nan) || ($y->{sign} eq $nan)); |
555 | |
574bacfe |
556 | # handle result = 0 |
557 | return $x->bzero() if $x->is_zero() || $y->is_zero(); |
558 | # inf handling |
559 | if (($x->{sign} =~ /^[+-]inf$/) || ($y->{sign} =~ /^[+-]inf$/)) |
560 | { |
561 | # result will always be +-inf: |
562 | # +inf * +/+inf => +inf, -inf * -/-inf => +inf |
563 | # +inf * -/-inf => -inf, -inf * +/+inf => -inf |
564 | return $x->binf() if ($x->{sign} =~ /^\+/ && $y->{sign} =~ /^\+/); |
565 | return $x->binf() if ($x->{sign} =~ /^-/ && $y->{sign} =~ /^-/); |
566 | return $x->binf('-'); |
567 | } |
568 | |
58cde26e |
569 | # aEb * cEd = (a*c)E(b+d) |
570 | $x->{_m} = $x->{_m} * $y->{_m}; |
571 | #print "m: $x->{_m}\n"; |
572 | $x->{_e} = $x->{_e} + $y->{_e}; |
573 | #print "e: $x->{_m}\n"; |
574 | # adjust sign: |
575 | $x->{sign} = $x->{sign} ne $y->{sign} ? '-' : '+'; |
576 | #print "s: $x->{sign}\n"; |
0716bf9b |
577 | $x->bnorm(); |
58cde26e |
578 | return $x->round($a,$p,$r,$y); |
579 | } |
580 | |
581 | sub bdiv |
582 | { |
583 | # (dividend: BFLOAT or num_str, divisor: BFLOAT or num_str) return |
584 | # (BFLOAT,BFLOAT) (quo,rem) or BINT (only rem) |
585 | my ($self,$x,$y,$a,$p,$r) = objectify(2,@_); |
586 | |
574bacfe |
587 | # x / +-inf => 0, reminder x |
588 | return wantarray ? ($x->bzero(),$x->copy()) : $x->bzero() |
589 | if $y->{sign} =~ /^[+-]inf$/; |
590 | |
591 | # NaN if x == NaN or y == NaN or x==y==0 |
58cde26e |
592 | return wantarray ? ($x->bnan(),bnan()) : $x->bnan() |
574bacfe |
593 | if (($x->is_nan() || $y->is_nan()) || |
594 | ($x->is_zero() && $y->is_zero())); |
595 | |
596 | # 5 / 0 => +inf, -6 / 0 => -inf |
597 | return wantarray |
598 | ? ($x->binf($x->{sign}),$self->bnan()) : $x->binf($x->{sign}) |
599 | if ($x->{sign} =~ /^[+-]$/ && $y->is_zero()); |
0716bf9b |
600 | |
601 | $y = $class->new($y) if ref($y) ne $class; # promote bigints |
602 | |
603 | # print "mbf bdiv $x ",ref($x)," ",$y," ",ref($y),"\n"; |
58cde26e |
604 | # we need to limit the accuracy to protect against overflow |
0716bf9b |
605 | my ($scale) = $x->_scale_a($accuracy,$rnd_mode,$a,$r); # ignore $p |
574bacfe |
606 | my $fallback = 0; |
58cde26e |
607 | if (!defined $scale) |
608 | { |
0716bf9b |
609 | # simulate old behaviour |
610 | $scale = $div_scale+1; # one more for proper riund |
574bacfe |
611 | $a = $div_scale; # and round to it |
612 | $fallback = 1; # to clear a/p afterwards |
a0d0e21e |
613 | } |
0716bf9b |
614 | my $lx = $x->{_m}->length(); my $ly = $y->{_m}->length(); |
58cde26e |
615 | $scale = $lx if $lx > $scale; |
58cde26e |
616 | $scale = $ly if $ly > $scale; |
617 | #print "scale $scale $lx $ly\n"; |
0716bf9b |
618 | my $diff = $ly - $lx; |
619 | $scale += $diff if $diff > 0; # if lx << ly, but not if ly << lx! |
a0d0e21e |
620 | |
58cde26e |
621 | return wantarray ? ($x,$self->bzero()) : $x if $x->is_zero(); |
622 | |
623 | $x->{sign} = $x->{sign} ne $y->sign() ? '-' : '+'; |
a0d0e21e |
624 | |
58cde26e |
625 | # check for / +-1 ( +/- 1E0) |
626 | if ($y->is_one()) |
627 | { |
628 | return wantarray ? ($x,$self->bzero()) : $x; |
a0d0e21e |
629 | } |
a5f75d66 |
630 | |
58cde26e |
631 | # a * 10 ** b / c * 10 ** d => a/c * 10 ** (b-d) |
632 | #print "self: $self x: $x ref(x) ", ref($x)," m: $x->{_m}\n"; |
633 | # my $scale_10 = 10 ** $scale; $x->{_m}->bmul($scale_10); |
634 | $x->{_m}->blsft($scale,10); |
0716bf9b |
635 | #print "m: $x->{_m} $y->{_m}\n"; |
58cde26e |
636 | $x->{_m}->bdiv( $y->{_m} ); # a/c |
637 | #print "m: $x->{_m}\n"; |
638 | #print "e: $x->{_e} $y->{_e}",$scale,"\n"; |
639 | $x->{_e}->bsub($y->{_e}); # b-d |
640 | #print "e: $x->{_e}\n"; |
641 | $x->{_e}->bsub($scale); # correct for 10**scale |
0716bf9b |
642 | #print "after div: m: $x->{_m} e: $x->{_e}\n"; |
643 | $x->bnorm(); # remove trailing 0's |
644 | #print "after div: m: $x->{_m} e: $x->{_e}\n"; |
645 | $x->round($a,$p,$r); # then round accordingly |
574bacfe |
646 | if ($fallback) |
647 | { |
648 | # clear a/p after round, since user did not request it |
649 | $x->{_a} = undef; |
650 | $x->{_p} = undef; |
651 | } |
0716bf9b |
652 | |
58cde26e |
653 | if (wantarray) |
654 | { |
655 | my $rem = $x->copy(); |
656 | $rem->bmod($y,$a,$p,$r); |
574bacfe |
657 | if ($fallback) |
658 | { |
659 | # clear a/p after round, since user did not request it |
660 | $x->{_a} = undef; |
661 | $x->{_p} = undef; |
662 | } |
0716bf9b |
663 | return ($x,$rem); |
58cde26e |
664 | } |
665 | return $x; |
666 | } |
a0d0e21e |
667 | |
58cde26e |
668 | sub bmod |
669 | { |
670 | # (dividend: BFLOAT or num_str, divisor: BFLOAT or num_str) return reminder |
671 | my ($self,$x,$y,$a,$p,$r) = objectify(2,@_); |
a0d0e21e |
672 | |
58cde26e |
673 | return $x->bnan() if ($x->{sign} eq $nan || $y->is_nan() || $y->is_zero()); |
674 | return $x->bzero() if $y->is_one(); |
675 | |
676 | # XXX tels: not done yet |
677 | return $x->round($a,$p,$r,$y); |
678 | } |
679 | |
680 | sub bsqrt |
681 | { |
0716bf9b |
682 | # calculate square root; this should probably |
683 | # use a different test to see whether the accuracy we want is... |
58cde26e |
684 | my ($self,$x,$a,$p,$r) = objectify(1,@_); |
685 | |
0716bf9b |
686 | return $x->bnan() if $x->{sign} eq 'NaN' || $x->{sign} =~ /^-/; # <0, NaN |
687 | return $x if $x->{sign} eq '+inf'; # +inf |
58cde26e |
688 | return $x if $x->is_zero() || $x == 1; |
689 | |
0716bf9b |
690 | # we need to limit the accuracy to protect against overflow |
691 | my ($scale) = $x->_scale_a($accuracy,$rnd_mode,$a,$r); # ignore $p |
574bacfe |
692 | my $fallback = 0; |
0716bf9b |
693 | if (!defined $scale) |
694 | { |
695 | # simulate old behaviour |
696 | $scale = $div_scale+1; # one more for proper riund |
697 | $a = $div_scale; # and round to it |
574bacfe |
698 | $fallback = 1; # to clear a/p afterwards |
0716bf9b |
699 | } |
700 | my $lx = $x->{_m}->length(); |
701 | $scale = $lx if $scale < $lx; |
58cde26e |
702 | my $e = Math::BigFloat->new("1E-$scale"); # make test variable |
703 | return $x->bnan() if $e->sign() eq 'NaN'; |
704 | |
58cde26e |
705 | # start with some reasonable guess |
0716bf9b |
706 | #$x *= 10 ** ($len - $org->{_e}); $x /= 2; # !?!? |
574bacfe |
707 | $lx = $lx+$x->{_e}; |
0716bf9b |
708 | $lx = 1 if $lx < 1; |
709 | my $gs = Math::BigFloat->new('1'. ('0' x $lx)); |
710 | |
711 | # print "first guess: $gs (x $x) scale $scale\n"; |
58cde26e |
712 | |
713 | my $diff = $e; |
714 | my $y = $x->copy(); |
715 | my $two = Math::BigFloat->new(2); |
716 | $x = Math::BigFloat->new($x) if ref($x) ne $class; # promote BigInts |
717 | # $scale = 2; |
718 | while ($diff >= $e) |
719 | { |
58cde26e |
720 | return $x->bnan() if $gs->is_zero(); |
0716bf9b |
721 | $r = $y->copy(); $r->bdiv($gs,$scale); |
58cde26e |
722 | $x = ($r + $gs); |
0716bf9b |
723 | $x->bdiv($two,$scale); |
58cde26e |
724 | $diff = $x->copy()->bsub($gs)->babs(); |
58cde26e |
725 | $gs = $x->copy(); |
a0d0e21e |
726 | } |
0716bf9b |
727 | $x->round($a,$p,$r); |
574bacfe |
728 | if ($fallback) |
729 | { |
730 | # clear a/p after round, since user did not request it |
731 | $x->{_a} = undef; |
732 | $x->{_p} = undef; |
733 | } |
734 | $x; |
58cde26e |
735 | } |
736 | |
737 | sub bpow |
738 | { |
739 | # (BFLOAT or num_str, BFLOAT or num_str) return BFLOAT |
740 | # compute power of two numbers, second arg is used as integer |
741 | # modifies first argument |
742 | |
743 | my ($self,$x,$y,$a,$p,$r) = objectify(2,@_); |
744 | |
0716bf9b |
745 | return $x if $x->{sign} =~ /^[+-]inf$/; |
58cde26e |
746 | return $x->bnan() if $x->{sign} eq $nan || $y->{sign} eq $nan; |
574bacfe |
747 | return $x->bone() if $y->is_zero(); |
58cde26e |
748 | return $x if $x->is_one() || $y->is_one(); |
749 | my $y1 = $y->as_number(); # make bigint |
750 | if ($x == -1) |
751 | { |
752 | # if $x == -1 and odd/even y => +1/-1 because +-1 ^ (+-1) => +-1 |
0716bf9b |
753 | return $y1->is_odd() ? $x : $x->babs(1); |
288d023a |
754 | } |
58cde26e |
755 | return $x if $x->is_zero() && $y->{sign} eq '+'; # 0**y => 0 (if not y <= 0) |
574bacfe |
756 | # 0 ** -y => 1 / (0 ** y) => / 0! (1 / 0 => +inf) |
757 | return $x->binf() if $x->is_zero() && $y->{sign} eq '-'; |
58cde26e |
758 | |
759 | # calculate $x->{_m} ** $y and $x->{_e} * $y separately (faster) |
760 | $y1->babs(); |
761 | $x->{_m}->bpow($y1); |
762 | $x->{_e}->bmul($y1); |
763 | $x->{sign} = $nan if $x->{_m}->{sign} eq $nan || $x->{_e}->{sign} eq $nan; |
764 | $x->bnorm(); |
765 | if ($y->{sign} eq '-') |
766 | { |
767 | # modify $x in place! |
0716bf9b |
768 | my $z = $x->copy(); $x->bzero()->binc(); |
58cde26e |
769 | return $x->bdiv($z,$a,$p,$r); # round in one go (might ignore y's A!) |
a0d0e21e |
770 | } |
58cde26e |
771 | return $x->round($a,$p,$r,$y); |
772 | } |
773 | |
774 | ############################################################################### |
775 | # rounding functions |
776 | |
777 | sub bfround |
778 | { |
779 | # precision: round to the $Nth digit left (+$n) or right (-$n) from the '.' |
780 | # $n == 0 means round to integer |
781 | # expects and returns normalized numbers! |
782 | my $x = shift; $x = $class->new($x) unless ref $x; |
a0d0e21e |
783 | |
58cde26e |
784 | return $x if $x->modify('bfround'); |
785 | |
786 | my ($scale,$mode) = $x->_scale_p($precision,$rnd_mode,@_); |
787 | return $x if !defined $scale; # no-op |
788 | |
574bacfe |
789 | # never round a 0, +-inf, NaN |
790 | return $x if $x->{sign} !~ /^[+-]$/ || $x->is_zero(); |
58cde26e |
791 | # print "MBF bfround $x to scale $scale mode $mode\n"; |
58cde26e |
792 | |
793 | if ($scale < 0) |
794 | { |
795 | # print "bfround scale $scale e $x->{_e}\n"; |
796 | # round right from the '.' |
797 | return $x if $x->{_e} >= 0; # nothing to round |
798 | $scale = -$scale; # positive for simplicity |
799 | my $len = $x->{_m}->length(); # length of mantissa |
800 | my $dad = -$x->{_e}; # digits after dot |
801 | my $zad = 0; # zeros after dot |
802 | $zad = -$len-$x->{_e} if ($x->{_e} < -$len);# for 0.00..00xxx style |
803 | # print "scale $scale dad $dad zad $zad len $len\n"; |
804 | |
805 | # number bsstr len zad dad |
806 | # 0.123 123e-3 3 0 3 |
807 | # 0.0123 123e-4 3 1 4 |
808 | # 0.001 1e-3 1 2 3 |
809 | # 1.23 123e-2 3 0 2 |
810 | # 1.2345 12345e-4 5 0 4 |
811 | |
812 | # do not round after/right of the $dad |
813 | return $x if $scale > $dad; # 0.123, scale >= 3 => exit |
814 | |
815 | # round to zero if rounding inside the $zad, but not for last zero like: |
816 | # 0.0065, scale -2, round last '0' with following '65' (scale == zad case) |
817 | if ($scale < $zad) |
818 | { |
574bacfe |
819 | return $x->bzero(); |
58cde26e |
820 | } |
821 | if ($scale == $zad) # for 0.006, scale -2 and trunc |
822 | { |
823 | $scale = -$len; |
824 | } |
825 | else |
826 | { |
827 | # adjust round-point to be inside mantissa |
828 | if ($zad != 0) |
829 | { |
830 | $scale = $scale-$zad; |
831 | } |
832 | else |
833 | { |
834 | my $dbd = $len - $dad; $dbd = 0 if $dbd < 0; # digits before dot |
835 | $scale = $dbd+$scale; |
836 | } |
837 | } |
838 | # print "round to $x->{_m} to $scale\n"; |
a0d0e21e |
839 | } |
58cde26e |
840 | else |
841 | { |
842 | # 123 => 100 means length(123) = 3 - $scale (2) => 1 |
a5f75d66 |
843 | |
58cde26e |
844 | # calculate digits before dot |
845 | my $dbt = $x->{_m}->length(); $dbt += $x->{_e} if $x->{_e}->sign() eq '-'; |
846 | if (($scale > $dbt) && ($dbt < 0)) |
847 | { |
848 | # if not enough digits before dot, round to zero |
574bacfe |
849 | return $x->bzero(); |
58cde26e |
850 | } |
851 | if (($scale >= 0) && ($dbt == 0)) |
852 | { |
853 | # 0.49->bfround(1): scale == 1, dbt == 0: => 0.0 |
854 | # 0.51->bfround(0): scale == 0, dbt == 0: => 1.0 |
855 | # 0.5->bfround(0): scale == 0, dbt == 0: => 0 |
856 | # 0.05->bfround(0): scale == 0, dbt == 0: => 0 |
857 | # print "$scale $dbt $x->{_m}\n"; |
858 | $scale = -$x->{_m}->length(); |
859 | } |
860 | elsif ($dbt > 0) |
861 | { |
862 | # correct by subtracting scale |
863 | $scale = $dbt - $scale; |
864 | } |
865 | else |
866 | { |
867 | $scale = $x->{_m}->length() - $scale; |
868 | } |
a0d0e21e |
869 | } |
574bacfe |
870 | # print "using $scale for $x->{_m} with '$mode'\n"; |
871 | # pass sign to bround for rounding modes '+inf' and '-inf' |
58cde26e |
872 | $x->{_m}->{sign} = $x->{sign}; |
873 | $x->{_m}->bround($scale,$mode); |
874 | $x->{_m}->{sign} = '+'; # fix sign back |
875 | $x->bnorm(); |
876 | } |
877 | |
878 | sub bround |
879 | { |
880 | # accuracy: preserve $N digits, and overwrite the rest with 0's |
881 | my $x = shift; $x = $class->new($x) unless ref $x; |
882 | my ($scale,$mode) = $x->_scale_a($accuracy,$rnd_mode,@_); |
883 | return $x if !defined $scale; # no-op |
884 | |
885 | return $x if $x->modify('bround'); |
886 | |
887 | # print "bround $scale $mode\n"; |
888 | # 0 => return all digits, scale < 0 makes no sense |
889 | return $x if ($scale <= 0); |
574bacfe |
890 | # never round a 0, +-inf, NaN |
891 | return $x if $x->{sign} !~ /^[+-]$/ || $x->is_zero(); |
58cde26e |
892 | |
893 | # if $e longer than $m, we have 0.0000xxxyyy style number, and must |
894 | # subtract the delta from scale, to simulate keeping the zeros |
895 | # -5 +5 => 1; -10 +5 => -4 |
896 | my $delta = $x->{_e} + $x->{_m}->length() + 1; |
897 | # removed by tlr, since causes problems with fraction tests: |
898 | # $scale += $delta if $delta < 0; |
899 | |
900 | # if we should keep more digits than the mantissa has, do nothing |
901 | return $x if $x->{_m}->length() <= $scale; |
f216259d |
902 | |
58cde26e |
903 | # pass sign to bround for '+inf' and '-inf' rounding modes |
904 | $x->{_m}->{sign} = $x->{sign}; |
905 | $x->{_m}->bround($scale,$mode); # round mantissa |
906 | $x->{_m}->{sign} = '+'; # fix sign back |
574bacfe |
907 | $x->bnorm(); # del trailing zeros gen. by bround() |
58cde26e |
908 | } |
909 | |
910 | sub bfloor |
911 | { |
912 | # return integer less or equal then $x |
913 | my ($self,$x,$a,$p,$r) = objectify(1,@_); |
914 | |
915 | return $x if $x->modify('bfloor'); |
916 | |
917 | return $x if $x->{sign} !~ /^[+-]$/; # nan, +inf, -inf |
918 | |
919 | # if $x has digits after dot |
920 | if ($x->{_e}->{sign} eq '-') |
921 | { |
922 | $x->{_m}->brsft(-$x->{_e},10); |
923 | $x->{_e}->bzero(); |
924 | $x-- if $x->{sign} eq '-'; |
f216259d |
925 | } |
58cde26e |
926 | return $x->round($a,$p,$r); |
927 | } |
288d023a |
928 | |
58cde26e |
929 | sub bceil |
930 | { |
931 | # return integer greater or equal then $x |
932 | my ($self,$x,$a,$p,$r) = objectify(1,@_); |
933 | |
934 | return $x if $x->modify('bceil'); |
935 | return $x if $x->{sign} !~ /^[+-]$/; # nan, +inf, -inf |
936 | |
937 | # if $x has digits after dot |
938 | if ($x->{_e}->{sign} eq '-') |
939 | { |
940 | $x->{_m}->brsft(-$x->{_e},10); |
941 | $x->{_e}->bzero(); |
942 | $x++ if $x->{sign} eq '+'; |
a0d0e21e |
943 | } |
58cde26e |
944 | return $x->round($a,$p,$r); |
945 | } |
946 | |
947 | ############################################################################### |
a5f75d66 |
948 | |
58cde26e |
949 | sub DESTROY |
950 | { |
951 | # going trough AUTOLOAD for every DESTROY is costly, so avoid it by empty sub |
952 | } |
953 | |
954 | sub AUTOLOAD |
955 | { |
956 | # make fxxx and bxxx work |
957 | # my $self = $_[0]; |
958 | my $name = $AUTOLOAD; |
959 | |
960 | $name =~ s/.*:://; # split package |
961 | #print "$name\n"; |
962 | if (!method_valid($name)) |
963 | { |
964 | #no strict 'refs'; |
965 | ## try one level up |
966 | #&{$class."::SUPER->$name"}(@_); |
967 | # delayed load of Carp and avoid recursion |
968 | require Carp; |
969 | Carp::croak ("Can't call $class\-\>$name, not a valid method"); |
a0d0e21e |
970 | } |
58cde26e |
971 | no strict 'refs'; |
972 | my $bname = $name; $bname =~ s/^f/b/; |
973 | *{$class."\:\:$name"} = \&$bname; |
974 | &$bname; # uses @_ |
975 | } |
976 | |
977 | sub exponent |
978 | { |
979 | # return a copy of the exponent |
980 | my $self = shift; |
981 | $self = $class->new($self) unless ref $self; |
982 | |
983 | return bnan() if $self->is_nan(); |
984 | return $self->{_e}->copy(); |
985 | } |
986 | |
987 | sub mantissa |
988 | { |
989 | # return a copy of the mantissa |
990 | my $self = shift; |
991 | $self = $class->new($self) unless ref $self; |
992 | |
993 | return bnan() if $self->is_nan(); |
994 | my $m = $self->{_m}->copy(); # faster than going via bstr() |
995 | $m->bneg() if $self->{sign} eq '-'; |
996 | |
997 | return $m; |
998 | } |
999 | |
1000 | sub parts |
1001 | { |
1002 | # return a copy of both the exponent and the mantissa |
1003 | my $self = shift; |
1004 | $self = $class->new($self) unless ref $self; |
1005 | |
1006 | return (bnan(),bnan()) if $self->is_nan(); |
1007 | my $m = $self->{_m}->copy(); # faster than going via bstr() |
1008 | $m->bneg() if $self->{sign} eq '-'; |
1009 | return ($m,$self->{_e}->copy()); |
1010 | } |
1011 | |
1012 | ############################################################################## |
1013 | # private stuff (internal use only) |
1014 | |
1015 | sub _one |
1016 | { |
1017 | # internal speedup, set argument to 1, or create a +/- 1 |
0716bf9b |
1018 | my $self = shift; $self = ref($self) if ref($self); |
1019 | my $x = {}; bless $x, $self; |
1020 | $x->{_m} = Math::BigInt->new(1); |
1021 | $x->{_e} = Math::BigInt->new(0); |
58cde26e |
1022 | $x->{sign} = shift || '+'; |
1023 | return $x; |
1024 | } |
1025 | |
1026 | sub import |
1027 | { |
1028 | my $self = shift; |
1029 | #print "import $self\n"; |
1030 | for ( my $i = 0; $i < @_ ; $i++ ) |
1031 | { |
1032 | if ( $_[$i] eq ':constant' ) |
1033 | { |
1034 | # this rest causes overlord er load to step in |
1035 | # print "overload @_\n"; |
1036 | overload::constant float => sub { $self->new(shift); }; |
1037 | splice @_, $i, 1; last; |
1038 | } |
1039 | } |
1040 | # any non :constant stuff is handled by our parent, Exporter |
1041 | # even if @_ is empty, to give it a chance |
1042 | #$self->SUPER::import(@_); # does not work (would call MBI) |
1043 | $self->export_to_level(1,$self,@_); # need this instead |
1044 | } |
1045 | |
1046 | sub bnorm |
1047 | { |
1048 | # adjust m and e so that m is smallest possible |
1049 | # round number according to accuracy and precision settings |
1050 | my $x = shift; |
1051 | |
0716bf9b |
1052 | return $x if $x->{sign} !~ /^[+-]$/; # inf, nan etc |
58cde26e |
1053 | |
1054 | my $zeros = $x->{_m}->_trailing_zeros(); # correct for trailing zeros |
1055 | if ($zeros != 0) |
1056 | { |
1057 | $x->{_m}->brsft($zeros,10); $x->{_e} += $zeros; |
1058 | } |
1059 | # for something like 0Ey, set y to 1 |
574bacfe |
1060 | $x->{sign} = '+', $x->{_e}->bzero()->binc() if $x->{_m}->is_zero(); |
0716bf9b |
1061 | $x->{_m}->{_f} = MB_NEVER_ROUND; |
1062 | $x->{_e}->{_f} = MB_NEVER_ROUND; |
1063 | return $x; # MBI bnorm is no-op |
58cde26e |
1064 | } |
1065 | |
1066 | ############################################################################## |
1067 | # internal calculation routines |
1068 | |
1069 | sub as_number |
1070 | { |
1071 | # return a bigint representation of this BigFloat number |
1072 | my ($self,$x) = objectify(1,@_); |
1073 | |
1074 | my $z; |
1075 | if ($x->{_e}->is_zero()) |
1076 | { |
1077 | $z = $x->{_m}->copy(); |
1078 | $z->{sign} = $x->{sign}; |
1079 | return $z; |
1080 | } |
0716bf9b |
1081 | $z = $x->{_m}->copy(); |
58cde26e |
1082 | if ($x->{_e} < 0) |
1083 | { |
0716bf9b |
1084 | $z->brsft(-$x->{_e},10); |
1085 | } |
1086 | else |
1087 | { |
1088 | $z->blsft($x->{_e},10); |
58cde26e |
1089 | } |
58cde26e |
1090 | $z->{sign} = $x->{sign}; |
1091 | return $z; |
1092 | } |
1093 | |
1094 | sub length |
1095 | { |
1096 | my $x = shift; $x = $class->new($x) unless ref $x; |
1097 | |
1098 | my $len = $x->{_m}->length(); |
1099 | $len += $x->{_e} if $x->{_e}->sign() eq '+'; |
1100 | if (wantarray()) |
1101 | { |
1102 | my $t = Math::BigInt::bzero(); |
1103 | $t = $x->{_e}->copy()->babs() if $x->{_e}->sign() eq '-'; |
1104 | return ($len,$t); |
1105 | } |
1106 | return $len; |
1107 | } |
a0d0e21e |
1108 | |
1109 | 1; |
a5f75d66 |
1110 | __END__ |
1111 | |
1112 | =head1 NAME |
1113 | |
58cde26e |
1114 | Math::BigFloat - Arbitrary size floating point math package |
a5f75d66 |
1115 | |
1116 | =head1 SYNOPSIS |
1117 | |
a2008d6d |
1118 | use Math::BigFloat; |
58cde26e |
1119 | |
1120 | # Number creation |
1121 | $x = Math::BigInt->new($str); # defaults to 0 |
1122 | $nan = Math::BigInt->bnan(); # create a NotANumber |
1123 | $zero = Math::BigInt->bzero();# create a "+0" |
1124 | |
1125 | # Testing |
1126 | $x->is_zero(); # return whether arg is zero or not |
0716bf9b |
1127 | $x->is_nan(); # return whether arg is NaN or not |
1128 | $x->is_one(); # true if arg is +1 |
1129 | $x->is_one('-'); # true if arg is -1 |
1130 | $x->is_odd(); # true if odd, false for even |
1131 | $x->is_even(); # true if even, false for odd |
1132 | $x->is_positive(); # true if >= 0 |
1133 | $x->is_negative(); # true if < 0 |
1134 | $x->is_inf(sign) # true if +inf or -inf (sign default '+') |
58cde26e |
1135 | $x->bcmp($y); # compare numbers (undef,<0,=0,>0) |
1136 | $x->bacmp($y); # compare absolutely (undef,<0,=0,>0) |
1137 | $x->sign(); # return the sign, either +,- or NaN |
1138 | |
1139 | # The following all modify their first argument: |
1140 | |
1141 | # set |
1142 | $x->bzero(); # set $i to 0 |
1143 | $x->bnan(); # set $i to NaN |
1144 | |
1145 | $x->bneg(); # negation |
1146 | $x->babs(); # absolute value |
1147 | $x->bnorm(); # normalize (no-op) |
1148 | $x->bnot(); # two's complement (bit wise not) |
1149 | $x->binc(); # increment x by 1 |
1150 | $x->bdec(); # decrement x by 1 |
1151 | |
1152 | $x->badd($y); # addition (add $y to $x) |
1153 | $x->bsub($y); # subtraction (subtract $y from $x) |
1154 | $x->bmul($y); # multiplication (multiply $x by $y) |
1155 | $x->bdiv($y); # divide, set $i to quotient |
1156 | # return (quo,rem) or quo if scalar |
1157 | |
1158 | $x->bmod($y); # modulus |
1159 | $x->bpow($y); # power of arguments (a**b) |
1160 | $x->blsft($y); # left shift |
1161 | $x->brsft($y); # right shift |
1162 | # return (quo,rem) or quo if scalar |
1163 | |
1164 | $x->band($y); # bit-wise and |
1165 | $x->bior($y); # bit-wise inclusive or |
1166 | $x->bxor($y); # bit-wise exclusive or |
1167 | $x->bnot(); # bit-wise not (two's complement) |
1168 | |
1169 | $x->bround($N); # accuracy: preserver $N digits |
1170 | $x->bfround($N); # precision: round to the $Nth digit |
1171 | |
1172 | # The following do not modify their arguments: |
1173 | |
1174 | bgcd(@values); # greatest common divisor |
1175 | blcm(@values); # lowest common multiplicator |
1176 | |
1177 | $x->bstr(); # return string |
1178 | $x->bsstr(); # return string in scientific notation |
1179 | |
1180 | $x->exponent(); # return exponent as BigInt |
1181 | $x->mantissa(); # return mantissa as BigInt |
1182 | $x->parts(); # return (mantissa,exponent) as BigInt |
1183 | |
1184 | $x->length(); # number of digits (w/o sign and '.') |
1185 | ($l,$f) = $x->length(); # number of digits, and length of fraction |
a5f75d66 |
1186 | |
1187 | =head1 DESCRIPTION |
1188 | |
58cde26e |
1189 | All operators (inlcuding basic math operations) are overloaded if you |
1190 | declare your big floating point numbers as |
a5f75d66 |
1191 | |
58cde26e |
1192 | $i = new Math::BigFloat '12_3.456_789_123_456_789E-2'; |
1193 | |
1194 | Operations with overloaded operators preserve the arguments, which is |
1195 | exactly what you expect. |
1196 | |
1197 | =head2 Canonical notation |
1198 | |
1199 | Input to these routines are either BigFloat objects, or strings of the |
1200 | following four forms: |
a5f75d66 |
1201 | |
1202 | =over 2 |
1203 | |
58cde26e |
1204 | =item * |
1205 | |
1206 | C</^[+-]\d+$/> |
a5f75d66 |
1207 | |
58cde26e |
1208 | =item * |
a5f75d66 |
1209 | |
58cde26e |
1210 | C</^[+-]\d+\.\d*$/> |
a5f75d66 |
1211 | |
58cde26e |
1212 | =item * |
a5f75d66 |
1213 | |
58cde26e |
1214 | C</^[+-]\d+E[+-]?\d+$/> |
a5f75d66 |
1215 | |
58cde26e |
1216 | =item * |
a5f75d66 |
1217 | |
58cde26e |
1218 | C</^[+-]\d*\.\d+E[+-]?\d+$/> |
5d7098d5 |
1219 | |
58cde26e |
1220 | =back |
1221 | |
1222 | all with optional leading and trailing zeros and/or spaces. Additonally, |
1223 | numbers are allowed to have an underscore between any two digits. |
1224 | |
1225 | Empty strings as well as other illegal numbers results in 'NaN'. |
1226 | |
1227 | bnorm() on a BigFloat object is now effectively a no-op, since the numbers |
1228 | are always stored in normalized form. On a string, it creates a BigFloat |
1229 | object. |
1230 | |
1231 | =head2 Output |
1232 | |
1233 | Output values are BigFloat objects (normalized), except for bstr() and bsstr(). |
1234 | |
1235 | The string output will always have leading and trailing zeros stripped and drop |
1236 | a plus sign. C<bstr()> will give you always the form with a decimal point, |
1237 | while C<bsstr()> (for scientific) gives you the scientific notation. |
1238 | |
1239 | Input bstr() bsstr() |
1240 | '-0' '0' '0E1' |
1241 | ' -123 123 123' '-123123123' '-123123123E0' |
1242 | '00.0123' '0.0123' '123E-4' |
1243 | '123.45E-2' '1.2345' '12345E-4' |
1244 | '10E+3' '10000' '1E4' |
1245 | |
1246 | Some routines (C<is_odd()>, C<is_even()>, C<is_zero()>, C<is_one()>, |
1247 | C<is_nan()>) return true or false, while others (C<bcmp()>, C<bacmp()>) |
1248 | return either undef, <0, 0 or >0 and are suited for sort. |
1249 | |
1250 | Actual math is done by using BigInts to represent the mantissa and exponent. |
1251 | The sign C</^[+-]$/> is stored separately. The string 'NaN' is used to |
1252 | represent the result when input arguments are not numbers, as well as |
1253 | the result of dividing by zero. |
1254 | |
1255 | =head2 C<mantissa()>, C<exponent()> and C<parts()> |
1256 | |
1257 | C<mantissa()> and C<exponent()> return the said parts of the BigFloat |
1258 | as BigInts such that: |
1259 | |
1260 | $m = $x->mantissa(); |
1261 | $e = $x->exponent(); |
1262 | $y = $m * ( 10 ** $e ); |
1263 | print "ok\n" if $x == $y; |
1264 | |
1265 | C<< ($m,$e) = $x->parts(); >> is just a shortcut giving you both of them. |
1266 | |
1267 | A zero is represented and returned as C<0E1>, B<not> C<0E0> (after Knuth). |
1268 | |
1269 | Currently the mantissa is reduced as much as possible, favouring higher |
1270 | exponents over lower ones (e.g. returning 1e7 instead of 10e6 or 10000000e0). |
1271 | This might change in the future, so do not depend on it. |
1272 | |
1273 | =head2 Accuracy vs. Precision |
1274 | |
1275 | See also: L<Rounding|Rounding>. |
1276 | |
1277 | Math::BigFloat supports both precision and accuracy. (here should follow |
1278 | a short description of both). |
5d7098d5 |
1279 | |
58cde26e |
1280 | Precision: digits after the '.', laber, schwad |
1281 | Accuracy: Significant digits blah blah |
5d7098d5 |
1282 | |
58cde26e |
1283 | Since things like sqrt(2) or 1/3 must presented with a limited precision lest |
1284 | a operation consumes all resources, each operation produces no more than |
1285 | C<Math::BigFloat::precision()> digits. |
1286 | |
1287 | In case the result of one operation has more precision than specified, |
1288 | it is rounded. The rounding mode taken is either the default mode, or the one |
1289 | supplied to the operation after the I<scale>: |
1290 | |
1291 | $x = Math::BigFloat->new(2); |
1292 | Math::BigFloat::precision(5); # 5 digits max |
1293 | $y = $x->copy()->bdiv(3); # will give 0.66666 |
1294 | $y = $x->copy()->bdiv(3,6); # will give 0.666666 |
1295 | $y = $x->copy()->bdiv(3,6,'odd'); # will give 0.666667 |
1296 | Math::BigFloat::round_mode('zero'); |
1297 | $y = $x->copy()->bdiv(3,6); # will give 0.666666 |
1298 | |
1299 | =head2 Rounding |
1300 | |
1301 | =over 2 |
1302 | |
5dc6f178 |
1303 | =item ffround ( +$scale ) |
58cde26e |
1304 | |
0716bf9b |
1305 | Rounds to the $scale'th place left from the '.', counting from the dot. |
1306 | The first digit is numbered 1. |
58cde26e |
1307 | |
5dc6f178 |
1308 | =item ffround ( -$scale ) |
58cde26e |
1309 | |
0716bf9b |
1310 | Rounds to the $scale'th place right from the '.', counting from the dot. |
58cde26e |
1311 | |
5dc6f178 |
1312 | =item ffround ( 0 ) |
1313 | |
0716bf9b |
1314 | Rounds to an integer. |
5dc6f178 |
1315 | |
1316 | =item fround ( +$scale ) |
1317 | |
0716bf9b |
1318 | Preserves accuracy to $scale digits from the left (aka significant digits) |
1319 | and pads the rest with zeros. If the number is between 1 and -1, the |
1320 | significant digits count from the first non-zero after the '.' |
5dc6f178 |
1321 | |
1322 | =item fround ( -$scale ) and fround ( 0 ) |
1323 | |
0716bf9b |
1324 | These are effetively no-ops. |
5d7098d5 |
1325 | |
a5f75d66 |
1326 | =back |
1327 | |
0716bf9b |
1328 | All rounding functions take as a second parameter a rounding mode from one of |
1329 | the following: 'even', 'odd', '+inf', '-inf', 'zero' or 'trunc'. |
58cde26e |
1330 | |
1331 | The default rounding mode is 'even'. By using |
0716bf9b |
1332 | C<< Math::BigFloat::round_mode($rnd_mode); >> you can get and set the default |
1333 | mode for subsequent rounding. The usage of C<$Math::BigFloat::$rnd_mode> is |
1334 | no longer supported. |
b22b3e31 |
1335 | The second parameter to the round functions then overrides the default |
0716bf9b |
1336 | temporarily. |
58cde26e |
1337 | |
1338 | The C<< as_number() >> function returns a BigInt from a Math::BigFloat. It uses |
1339 | 'trunc' as rounding mode to make it equivalent to: |
1340 | |
1341 | $x = 2.5; |
1342 | $y = int($x) + 2; |
1343 | |
1344 | You can override this by passing the desired rounding mode as parameter to |
1345 | C<as_number()>: |
1346 | |
1347 | $x = Math::BigFloat->new(2.5); |
1348 | $y = $x->as_number('odd'); # $y = 3 |
1349 | |
1350 | =head1 EXAMPLES |
1351 | |
58cde26e |
1352 | # not ready yet |
58cde26e |
1353 | |
1354 | =head1 Autocreating constants |
1355 | |
1356 | After C<use Math::BigFloat ':constant'> all the floating point constants |
1357 | in the given scope are converted to C<Math::BigFloat>. This conversion |
1358 | happens at compile time. |
1359 | |
1360 | In particular |
1361 | |
1362 | perl -MMath::BigFloat=:constant -e 'print 2E-100,"\n"' |
1363 | |
1364 | prints the value of C<2E-100>. Note that without conversion of |
1365 | constants the expression 2E-100 will be calculated as normal floating point |
1366 | number. |
1367 | |
a5f75d66 |
1368 | =head1 BUGS |
1369 | |
58cde26e |
1370 | =over 2 |
1371 | |
1372 | =item * |
1373 | |
1374 | The following does not work yet: |
1375 | |
1376 | $m = $x->mantissa(); |
1377 | $e = $x->exponent(); |
1378 | $y = $m * ( 10 ** $e ); |
1379 | print "ok\n" if $x == $y; |
1380 | |
1381 | =item * |
1382 | |
1383 | There is no fmod() function yet. |
1384 | |
1385 | =back |
1386 | |
1387 | =head1 CAVEAT |
1388 | |
1389 | =over 1 |
1390 | |
1391 | =item stringify, bstr() |
1392 | |
1393 | Both stringify and bstr() now drop the leading '+'. The old code would return |
1394 | '+1.23', the new returns '1.23'. See the documentation in L<Math::BigInt> for |
1395 | reasoning and details. |
1396 | |
1397 | =item bdiv |
1398 | |
1399 | The following will probably not do what you expect: |
1400 | |
1401 | print $c->bdiv(123.456),"\n"; |
1402 | |
1403 | It prints both quotient and reminder since print works in list context. Also, |
1404 | bdiv() will modify $c, so be carefull. You probably want to use |
1405 | |
1406 | print $c / 123.456,"\n"; |
1407 | print scalar $c->bdiv(123.456),"\n"; # or if you want to modify $c |
1408 | |
1409 | instead. |
1410 | |
1411 | =item Modifying and = |
1412 | |
1413 | Beware of: |
1414 | |
1415 | $x = Math::BigFloat->new(5); |
1416 | $y = $x; |
1417 | |
1418 | It will not do what you think, e.g. making a copy of $x. Instead it just makes |
1419 | a second reference to the B<same> object and stores it in $y. Thus anything |
1420 | that modifies $x will modify $y, and vice versa. |
1421 | |
1422 | $x->bmul(2); |
1423 | print "$x, $y\n"; # prints '10, 10' |
1424 | |
1425 | If you want a true copy of $x, use: |
1426 | |
1427 | $y = $x->copy(); |
1428 | |
1429 | See also the documentation in L<overload> regarding C<=>. |
1430 | |
1431 | =item bpow |
1432 | |
1433 | C<bpow()> now modifies the first argument, unlike the old code which left |
1434 | it alone and only returned the result. This is to be consistent with |
1435 | C<badd()> etc. The first will modify $x, the second one won't: |
1436 | |
1437 | print bpow($x,$i),"\n"; # modify $x |
1438 | print $x->bpow($i),"\n"; # ditto |
1439 | print $x ** $i,"\n"; # leave $x alone |
1440 | |
1441 | =back |
1442 | |
1443 | =head1 LICENSE |
a5f75d66 |
1444 | |
58cde26e |
1445 | This program is free software; you may redistribute it and/or modify it under |
1446 | the same terms as Perl itself. |
5d7098d5 |
1447 | |
58cde26e |
1448 | =head1 AUTHORS |
5d7098d5 |
1449 | |
58cde26e |
1450 | Mark Biggar, overloaded interface by Ilya Zakharevich. |
1451 | Completely rewritten by Tels http://bloodgate.com in 2001. |
a5f75d66 |
1452 | |
a5f75d66 |
1453 | =cut |