=head1 DESCRIPTION
Text::Tradition is a library for representation and analysis of collated
-texts, particularly medieval ones. The Collation is the central feature of
-a Tradition, where the text, its sequence of readings, and its relationships
-between readings are actually kept.
+texts, particularly medieval ones. The Stemma is a representation of the
+copying relationships between the witnesses in a Tradition, modelled with
+a connected rooted directed acyclic graph (CRDAG).
=head1 DOT SYNTAX
-The easiest way to define a stemma (which is a directed acyclic graph, denoting
-the scholar's hypothesis concerning which text(s) were copied from which other(s))
-is to use a special form of the 'dot' syntax of GraphViz.
+The easiest way to define a stemma is to use a special form of the 'dot'
+syntax of GraphViz.
Each stemma opens with the line
sub as_dot {
my( $self, $opts ) = @_;
+ ## See if we are including any a.c. witnesses in this graph.
+ my $graph = $self->graph;
+ if( exists $opts->{'layerwits'} ) {
+ $graph = $self->extend_graph( $opts->{'layerwits'} );
+ }
+
# Get default and specified options
my %graphopts = (
# 'ratio' => 1,
if $opts->{'node'};
@edgeopts{ keys %{$opts->{'edge'}} } = values %{$opts->{'edge'}}
if $opts->{'edge'};
-
+
my @dotlines;
push( @dotlines, 'digraph stemma {' );
## Print out the global attributes
push( @dotlines, _make_dotline( 'node', %nodeopts ) ) if keys %nodeopts;
# Add each of the nodes.
- foreach my $n ( $self->graph->vertices ) {
- if( $self->graph->has_vertex_attribute( $n, 'label' ) ) {
- my $ltext = $self->graph->get_vertex_attribute( $n, 'label' );
+ foreach my $n ( $graph->vertices ) {
+ if( $graph->has_vertex_attribute( $n, 'label' ) ) {
+ my $ltext = $graph->get_vertex_attribute( $n, 'label' );
push( @dotlines, _make_dotline( $n, 'label' => $ltext ) );
} else {
# Use the default display settings.
}
}
# Add each of our edges.
- foreach my $e ( $self->graph->edges ) {
+ foreach my $e ( $graph->edges ) {
my( $from, $to ) = map { _dotquote( $_ ) } @$e;
push( @dotlines, " $from -> $to;" );
}
return join( "\n", @dotlines );
}
-=head2 editable( $linesep )
+=head2 editable( $opts )
Returns a version of the graph rendered in our definition format. The
-$linesep argument defaults to newline; set it to the empty string or to
-a space if the result is to be sent via JSON.
+output separates statements with a newline; set $opts->{'linesep'} to the
+empty string or to a space if the result is to be sent via JSON.
+
+Any layer witnesses to be included should be passed via $opts->{'layerwits'}.
=cut
sub editable {
- my $self = shift;
- my $join = shift || "\n";
+ my( $self, $opts ) = @_;
+
+ ## See if we are including any a.c. witnesses in this graph.
+ my $graph = $self->graph;
+ if( exists $opts->{'layerwits'} ) {
+ $graph = $self->extend_graph( $opts->{'layerwits'} );
+ }
+
+ # Create the graph
+ my $join = ( $opts && exists $opts->{'linesep'} ) ? $opts->{'linesep'} : "\n";
my @dotlines;
push( @dotlines, 'digraph stemma {' );
my @real; # A cheap sort
return $a->[0].$a->[1] cmp $b->[0].$b->[1];
}
+=head2 extend_graph( $layered_witnesses )
+
+Returns a graph which is the original stemma with witness layers added for the
+list in @$layered_witnesses. A layered (a.c.) witness is added as a parent
+of its main version, and additionally shares all other parents and children with
+that version.
+
+=cut
+
+sub extend_graph {
+ my( $self, $layerwits ) = @_;
+ # For each 'layered' witness in the layerwits array, add it to the graph
+ # as an ancestor of the 'main' witness, and otherwise with the same parent/
+ # child links as its main analogue.
+ # TOOD Handle case where B is copied from A but corrected from C
+
+ # Iterate through, adding a.c. witnesses
+ my $actag = $self->collation->ac_label;
+ my $graph = $self->graph->copy;
+ foreach my $lw ( @$layerwits ) {
+ # Add the layered witness and set it with the same attributes as
+ # its 'main' analogue
+ my $lwac = $lw . $self->collation->ac_label;
+ $graph->add_vertex( $lwac );
+ $graph->set_vertex_attributes( $lwac,
+ $graph->get_vertex_attributes( $lw ) );
+
+ # Set it as ancestor to the main witness
+ $graph->add_edge( $lwac, $lw );
+
+ # Give it the same ancestors and descendants as the main witness has,
+ # bearing in mind that those ancestors and descendants might also just
+ # have had a layered witness defined.
+ foreach my $v ( $graph->predecessors( $lw ) ) {
+ next if $v eq $lwac; # Don't add a loop
+ $graph->add_edge( $v, $lwac );
+ $graph->add_edge( $v.$self->collation->ac_label, $lwac )
+ if $graph->has_vertex( $v.$self->collation->ac_label );
+ }
+ foreach my $v ( $graph->successors( $lw ) ) {
+ next if $v eq $lwac; # but this shouldn't occur
+ $graph->add_edge( $lwac, $v );
+ $graph->add_edge( $lwac, $v.$self->collation->ac_label )
+ if $graph->has_vertex( $v.$self->collation->ac_label );
+ }
+ }
+ return $graph;
+}
+
=head2 as_svg
Returns an SVG representation of the graph, calling as_dot first.
projects / scpubgit/stemmatology.git / blobdiff