JFREEMAN / Algorithm-HowSimilar-0.01 / html / HowSimilar.html 
<HTML>
<HEAD>
<TITLE>HowSimilar.pm</TITLE>
<LINK REL="stylesheet" HREF="../html/docs.css" TYPE="text/css">
<LINK REV="made" HREF="mailto:">
</HEAD>

<BODY>
<TABLE BORDER=0 CELLPADDING=0 CELLSPACING=0 WIDTH=100%>
<TR><TD CLASS=block VALIGN=MIDDLE WIDTH=100% BGCOLOR="#cccccc">
<FONT SIZE=+1><STRONG><P CLASS=block>&nbsp;HowSimilar.pm</P></STRONG></FONT>
</TD></TR>
</TABLE>

<A NAME="__index__"></A>
<!-- INDEX BEGIN -->

<UL>

    <LI><A HREF="#name">NAME</A></LI>
    <LI><A HREF="#synopsis">SYNOPSIS</A></LI>
    <LI><A HREF="#description">DESCRIPTION</A></LI>
    <LI><A HREF="#methods">METHODS</A></LI>
    <UL>

        <LI><A HREF="#compare( arg1, arg2, optional_callback )">compare( ARG1, ARG2, OPTIONAL_CALLBACK )</A></LI>
        <LI><A HREF="#export">EXPORT</A></LI>
    </UL>

    <LI><A HREF="#author">AUTHOR</A></LI>
    <LI><A HREF="#see also">SEE ALSO</A></LI>
</UL>
<!-- INDEX END -->

<HR>
<P>
<H1><A NAME="name">NAME</A></H1>
<P>Algorithm::HowSimilar - Perl extension for quantifying similarites between things</P>
<P>
<HR>
<H1><A NAME="synopsis">SYNOPSIS</A></H1>
<PRE>
  use Algorithm::HowSimilar qw(compare);
  @res = compare( $str1, $str2, sub { s/\s+//g; [split //] } );
  @res = compare( \@ary1, \@ary2 );</PRE>
<P>
<HR>
<H1><A NAME="description">DESCRIPTION</A></H1>
<P>This module leverages Algorithm::Diff to let you compare the degree of sameness
of array or strings. It returns a result set that defines exactly how similar
these things are.</P>
<P>
<HR>
<H1><A NAME="methods">METHODS</A></H1>
<P>
<H2><A NAME="compare( arg1, arg2, optional_callback )">compare( ARG1, ARG2, OPTIONAL_CALLBACK )</A></H2>
<P>You can call compare with either two strings compare( $str1, $str2 ):</P>
<PRE>
    my ( $av_similarity,
         $sim_str1_to_str2,
         $sim_str2_to_str1,
         $matches,
         $in_str1_but_not_str2,
         $in_str2_but_not_str1
       ) = compare( 'this is a string-a', 'this is a string bbb' );</PRE>
<P>Note that the mathematical similarities of one string to another will be
different unless the strings have the same length. The first result returned
is the average similarity. Totally dissimilar strings will return 0. Identical
strings will return 1. The degree of similarity therefore ranges from 0-1 and
is reported as the biggest float your OS/Perl can manage.</P>
<P>You can also compare two array refs compare( \@ary1, \@ary2 ):</P>
<PRE>
    my ( $av_similarity,
         $sim_ary1_to_ary2,
         $sim_ary2_to_ary1,
         $ref_ary_matches,
         $ref_ary_in_ary1_but_not_ary2,
         $ref_ary_in_ary2_but_not_ary1
       ) = compare( [ 1,2,3,4 ], [ 3,4,5,6,7 ] );</PRE>
<P>When called with two string you can specify an optional callback that changes
the default tokenization of strings (a simple split on null) to whatever you
need. The strings are passed to you callback in $_ and the sub is expected to
return an array ref. So for example to ignore all
whitespace you could:</P>
<PRE>
    @res = compare( 'this is a string',
                    'this is a string ',
                    sub { s/\s+//g; [split //] }
                  );</PRE>
<P>You already get the intersection of the strings or arrays. You can get the
union like this:</P>
<PRE>
    @res = compare( $str1, $str2 );
    $intersection = $res[3];
    $union = $res[3].$res[4].$res[5];
    @res = compare( \@ary1, \@ary2 );
    @intersection = @{$res[3]};
    @union = ( @{$res[3]}, @{$res[4]}, @{$res[5]} );</PRE>
<P>
<H2><A NAME="export">EXPORT</A></H2>
<P>None by default.</P>
<P>
<HR>
<H1><A NAME="author">AUTHOR</A></H1>
<P>Dr James Freeman &lt;<A HREF="mailto:james.freeman@id3.org.uk">james.freeman@id3.org.uk</A>&gt;</P>
<P>
<HR>
<H1><A NAME="see also">SEE ALSO</A></H1>
<P><EM>perl</EM>.</P>
<TABLE BORDER=0 CELLPADDING=0 CELLSPACING=0 WIDTH=100%>
<TR><TD CLASS=block VALIGN=MIDDLE WIDTH=100% BGCOLOR="#cccccc">
<FONT SIZE=+1><STRONG><P CLASS=block>&nbsp;HowSimilar.pm</P></STRONG></FONT>
</TD></TR>
</TABLE>

</BODY>

</HTML>