Search::Tools::HeatMap - locate the best matches in a snippet extract

 use Search::Tools::Tokenizer;
 use Search::Tools::HeatMap;

 my $tokens = $self->tokenizer->tokenize( $my_string, qr/^(interesting)$/ );
 my $heatmap = Search::Tools::HeatMap->new(
     tokens         => $tokens,
     window_size    => 20,  # default
     as_sentences   => 0,   # default
 );

 if ( $heatmap->has_spans ) {

     my $tokens_arr = $tokens->as_array;

     # stringify positions
     my @snips;
     for my $span ( @{ $heatmap->spans } ) {
         push( @snips, $span->{str} );
     }
     my $occur_index = $self->occur - 1;
     if ( $#snips > $occur_index ) {
         @snips = @snips[ 0 .. $occur_index ];
     }
     printf("%s\n", join( ' ... ', @snips ));

 }

Search::Tools::HeatMap implements a simple algorithm for locating the densest clusters of unique, hot terms in a TokenList.

HeatMap is used internally by Snipper but documented here in case someone wants to abuse and/or improve it.

Create a new HeatMap. The TokenList object may be either a Search::Tools::TokenList or Search::Tools::TokenListPP object.

Builds the HeatMap object. Called internally by new().

The max width of a span. Defaults to 20 tokens, including the matches.

Set this in new(). Access it later if you need to, but the spans will have already been created by new().

Try to match clusters at sentence boundaries. Default is false.

Set this in new().

Returns an array ref of matching clusters. Each span in the array is a hash ref with the following keys:

cluster

pos

heat

str

str_w_pos

This item is available only if debug() is true.

unique

Returns the number of spans found.

Peter Karman <karman at cpan dot org>

The idea of the HeatMap comes from KinoSearch, though the implementation here is original.

Please report any bugs or feature requests to bug-search-tools at rt.cpan.org, or through the web interface at http://rt.cpan.org/NoAuth/ReportBug.html?Queue=Search-Tools. I will be notified, and then you'll automatically be notified of progress on your bug as I make changes.

You can find documentation for this module with the perldoc command.

    perldoc Search::Tools

You can also look for information at:

* RT: CPAN's request tracker

http://rt.cpan.org/NoAuth/Bugs.html?Dist=Search-Tools

* AnnoCPAN: Annotated CPAN documentation

http://annocpan.org/dist/Search-Tools

* CPAN Ratings

http://cpanratings.perl.org/d/Search-Tools

* Search CPAN

http://search.cpan.org/dist/Search-Tools/

Copyright 2009 by Peter Karman.

This package is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

KinoSearch