From Code to Community: Sponsoring The Perl and Raku Conference 2025 Learn more

OVERLAST / Algorithm-SetSimilarity-0.0.0_03 / lib / Algorithm / SetSimilarity / Jaccard.pm 

            

              
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
—
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221

              
package Algorithm::SetSimilarity::Jaccard;
use 5.008005;
use strict;
use warnings;
our $VERSION = "0.0.0_03";
use Scalar::Util;
sub new {
    my ($class, $param) = @_;
    my %hash = ();
    $hash{"is_sorted"} = $param->{is_sorted} if (exists $param->{is_sorted});
    $hash{"data_type"} = $param->{data_type} if (exists $param->{data_type});
    bless \%hash, $class;
}
sub estimate_data_type {
    my ($self, $set1, $set2) = @_;
    my $is_estimate = 0;
    my ($type1, $type2) = ("string","string");
    if (Scalar::Util::looks_like_number($set1->[0])) {
        $type1 = "number";
    }
    if (Scalar::Util::looks_like_number($set2->[0])) {
        $type2 = "number";
    }
    if ($type1 eq $type2) {
        $self->{data_type} = $type1;
        $is_estimate = 1;
    }
    return $is_estimate;
}
sub get_similarity {
    my ($self, $set1, $set2, $threshold) = @_;
    my $score = -1.0;
    if ((ref $set1 eq "ARRAY") && (ref $set2 eq "ARRAY") && (@$set1) && (@$set2)) {
        if ((defined $threshold) && ($threshold > 0.0)) {
            $score = $self->filt_by_threshold($set1, $set2, $threshold);
        } else{
            ($set1, $set2) = $self->_swap_set_descending_order($set1, $set2);
            my $s1 = $#$set1 + 1;
            my $s2 = $#$set2 + 1;
            my $is_estimate = $self->estimate_data_type($set1, $set2) unless (exists $self->{data_type});
            if (($is_estimate) || (exists $self->{data_type})) {
                unless ( $self->{is_sorted} ) {
                    if ($self->{data_type} eq "number") {
                        @{$set1} = sort {$a <=> $b} @$set1;
                        @{$set2} = sort {$a <=> $b} @$set2;
                    } else {
                        @{$set1} = sort {$a cmp $b} @$set1;
                        @{$set2} = sort {$a cmp $b} @$set2;
                    }
                }
                my $match_num = 0;
                for (my ($att1, $att2) = (0, 0); ($att1 < $s2) && ($att2 < $s2);) {
                    my $judge = -1;
                    if ($self->{data_type} eq "number") {
                        $judge = ($set1->[$att1] <=> $set2->[$att2]);
                    } else {
                        $judge = ($set1->[$att1] cmp $set2->[$att2]);
                    }
                    if ($judge == -1) {
                        $att1++;
                    } elsif ($judge == 1) {
                        $att2++;
                    } else {
                        $match_num++;
                        $att1++;
                        $att2++;
                    }
                }
                my $diff_num = ($s1 - $match_num) + ($s2 - $match_num);
                $score = $match_num / ($match_num + $diff_num);
            }
        }
    }
    return $score;
}
sub _swap_set_ascending_order {
    my ($self, $set1, $set2) = @_;
    if ($#$set1 > $#$set2) {
        my $tmp_ref = $set1;
        $set1 = $set2;
        $set2 = $tmp_ref;
    }
    return wantarray ? ($set1, $set2) : [$set1, $set2];
}
 sub _swap_set_descending_order {
     my ($self, $set1, $set2) = @_;
     if ($#$set1 < $#$set2) {
         my $tmp_ref = $set1;
         $set1 = $set2;
         $set2 = $tmp_ref;
     }
     return wantarray ? ($set1, $set2) : [$set1, $set2];
 }
sub filt_by_threshold {
    my ($self, $set1, $set2, $threshold) = @_;
    my $score = -1.0;
    if ((ref $set1 eq "ARRAY") && (ref $set2 eq "ARRAY") &&
            (@$set1) && (@$set2) &&
                ($threshold > 0.0) && ($threshold <= 1.0)) {
        for(my $r = 0; $r <= 0; $r++) {
            ($set1, $set2) = $self->_swap_set_descending_order($set1, $set2);
            my $s1 = $#$set1 + 1;
            my $s2 = $#$set2 + 1;
            last unless (($s1 * $threshold) <= $s2); #size filtering
            my $is_estimate = $self->estimate_data_type($set1, $set2) unless (exists $self->{data_type});
            if (($is_estimate) || (exists $self->{data_type})) {
                unless ( $self->{is_sorted} ) {
                    if ($self->{data_type} eq "number") {
                        @{$set1} = sort { $a <=> $b } @$set1;
                        @{$set2} = sort { $a <=> $b } @$set2;
                    } else {
                        @{$set1} = sort { $a cmp $b} @$set1;
                        @{$set2} = sort { $a cmp $b} @$set2;
                    }
                }
                my $min_overlap = int(($threshold / (1 + $threshold)) * ($s1 + $s2));
                my $alpha = $s2 - ($min_overlap + 1) + 1;
                my $match_num = 0;
                my ($att1, $att2) = (0, 0);
                while (($att2 < $alpha) && ($att1 < $s1)) {
                    my $judge = -1;
                    if ($self->{data_type} eq "number") {
                        $judge = ($set1->[$att1] <=> $set2->[$att2]);
                    } else {
                        $judge = ($set1->[$att1] cmp $set2->[$att2]);
                    }
                    if ($judge == -1) {
                        $att1++;
                    } elsif ($judge == 1) {
                        $att2++;
                    } else {
                        $match_num++;
                        $att1++;
                        $att2++;
                    }
                }
                my $min = ($s2 - $att2);
                $min = ($s1 - $att1) if ($min > ($s1 - $att1));
                if (($match_num) + $min < $min_overlap) {
                    $match_num = 0;
                    last;
                }
                last unless ($match_num >= 1);
                while (($att1 < $s1) && ($att2 < $s2)) {
                    my $judge = -1;
                    if ($self->{data_type} eq "number") {
                        $judge = ($set1->[$att1] <=> $set2->[$att2]);
                    } else {
                        $judge = ($set1->[$att1] cmp $set2->[$att2]);
                    }
                    if ($judge == -1) {
                        last if ($match_num + ($s1 - $att1) < $min_overlap);
                        $att1++;
                    } elsif ($judge == 1) {
                        last if ($match_num + ($s2 - $att2) < $min_overlap);
                        $att2++;
                    } else {
                        $match_num++;
                        $att1++;
                        $att2++;
                    }
                }
                last unless ($match_num >= $min_overlap + 1);
                my $diff_num = ($s1 - $match_num) + ($s2 - $match_num);
                $score = $match_num / ($match_num + $diff_num);
            }
        }
    }
    return $score;
}
1;
__END__
=encoding utf-8
=head1 NAME
Algorithm::SetSimilarity::Jaccard - It's new $module
=head1 SYNOPSIS
    use Algorithm::SetSimilarity::Jaccard;
=head1 DESCRIPTION
Algorithm::SetSimilarity::Jaccard is ...
=head1 LICENSE
Copyright (C) Toshinori Sato (@overlast).
This library is free software; you can redistribute it and/or modify
it under the same terms as Perl itself.
=head1 AUTHOR
Toshinori Sato (@overlast) E<lt>overlasting@gmail.comE<gt>
=cut