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| -rw-r--r-- | mteval-v14.pl | 1179 |
1 files changed, 1179 insertions, 0 deletions
diff --git a/mteval-v14.pl b/mteval-v14.pl new file mode 100644 index 0000000..84a7549 --- /dev/null +++ b/mteval-v14.pl @@ -0,0 +1,1179 @@ +#!/usr/bin/env perl + +use warnings; +use strict; +use utf8; +use Encode; +use XML::Twig; +use Sort::Naturally; + +binmode STDOUT, ":utf8"; +binmode STDERR, ":utf8"; + + +################################# +# History: +# +# version 14 +# (2016-03-29 lukas.diduch@nist.gov) +# * Fixed warning message in case seg-id is a string, by sorting in correct order using Sort::Naturally. +# +# version 13b +# * Fixed die 'bug' in case seg->id = 0 +# +# version 13a +# * modified the scoring functions to prevent division-by-zero errors when a system segment is empty +# * affected methods: 'bleu_score' and 'bleu_score_smoothing' +# +# version 13 +# * Uses a XML parser to read data (only when extension is .xml) +# * Smoothing of the segment-level BLEU scores, done by default +# * smoothing method similar to that of bleu-1.04.pl (IBM) +# * see comments above the 'bleu_score' method for more details on how the smoothing is computed +# * added a '--no-smoothing' option to simulate old scripts behavior +# * Introduction of the 'brevity-penalty' option, taking one of two values: +# * 'closest' (default) : act as IBM BLEU (taking the closest reference translation length) +# * in case two reference translations are at the same distance, will take the shortest one +# * for more details regarding how the BP is computed, see comments of the 'brevity_penalty_closest' function +# * 'shortest' : act as previous versions of the script (taking shortest reference translation length) +# * Introduction of the 'international-tokenization' option, boolean, disabled by default +# by default (when the option is not provided), uses 11b's tokenization function +# when option specified, uses v12's tokenization function +# * Introduction of a 'Metrics MATR output' flag (option '--metricsMATR') +# when used, creates three files for both BLEU score and NIST score: +# * BLEU-seg.scr and NIST-seg.scr: contain segment-level scores +# * BLEU-doc.scr and NIST-doc.scr: contain document-level scores +# * BLEU-sys.scr and NIST-sys.scr: contain system-level scores +# * SGML parsing +# * script will halt if source, reference and test files don't share the same setid attribute value (used for metricsMATR output) +# * correct segment IDs extracted from the files (was previously using an array, and using the index as a segID for output) +# * detailed output flag (-d) can now be used when running both BLEU and NIST +# +# version 12 +# * Text normalization changes: +# * convert entity references (only the entities declared in the DTD) +# * now uses unicode categories +# * tokenize punctuation unless followed AND preceded by digits +# * tokenize symbols +# * UTF-8 handling: +# * files are now read using utf8 mode +# * Added the '-e' command-line option to enclose non-ASCII characters between spaces +# +# version 11b -- text normalization modified: +# * take out the join digit line because it joins digits +# when it shouldn't have +# $norm_text =~ s/(\d)\s+(?=\d)/$1/g; #join digits +# +# version 11a -- corrected output of individual n-gram precision values +# +# version 11 -- bug fixes: +# * make filehandle operate in binary mode to prevent Perl from operating +# (by default in Red Hat 9) in UTF-8 +# * fix failure on joining digits +# version 10 -- updated output to include more details of n-gram scoring. +# Defaults to generate both NIST and BLEU scores. Use -b for BLEU +# only, use -n for NIST only +# +# version 09d -- bug fix (for BLEU scoring, ngrams were fixed at 4 +# being the max, regardless what was entered on the command line.) +# +# version 09c -- bug fix (During the calculation of ngram information, +# each ngram was being counted only once for each segment. This has +# been fixed so that each ngram is counted correctly in each segment.) +# +# version 09b -- text normalization modified: +# * option flag added to preserve upper case +# * non-ASCII characters left in place. +# +# version 09a -- text normalization modified: +# * " and & converted to "" and &, respectively +# * non-ASCII characters kept together (bug fix) +# +# version 09 -- modified to accommodate sgml tag and attribute +# names revised to conform to default SGML conventions. +# +# version 08 -- modifies the NIST metric in accordance with the +# findings on the 2001 Chinese-English dry run corpus. Also +# incorporates the BLEU metric as an option and supports the +# output of ngram detail. +# +# version 07 -- in response to the MT meeting on 28 Jan 2002 at ISI +# Keep strings of non-ASCII characters together as one word +# (rather than splitting them into one-character words). +# Change length penalty so that translations that are longer than +# the average reference translation are not penalized. +# +# version 06 +# Prevent divide-by-zero when a segment has no evaluation N-grams. +# Correct segment index for level 3 debug output. +# +# version 05 +# improve diagnostic error messages +# +# version 04 +# tag segments +# +# version 03 +# add detailed output option (intermediate document and segment scores) +# +# version 02 +# accommodation of modified sgml tags and attributes +# +# version 01 +# same as bleu version 15, but modified to provide formal score output. +# +# original IBM version +# Author: Kishore Papineni +# Date: 06/10/2001 +################################# + +###### +# Intro +my ($date, $time) = date_time_stamp(); +print "MT evaluation scorer began on $date at $time\n"; +print "\ncommand line: ", $0, " ", join(" ", @ARGV), "\n"; +my $usage = "\n\nUsage: $0 -r <ref_file> -s <src_file> -t <tst_file>\n\n". + "Description: This Perl script evaluates MT system performance.\n". + "\n". + "Required arguments:\n". + " -r <ref_file> is a file containing the reference translations for\n". + " the documents to be evaluated.\n". + " -s <src_file> is a file containing the source documents for which\n". + " translations are to be evaluated\n". + " -t <tst_file> is a file containing the translations to be evaluated\n". + "\n". + "Optional arguments:\n". + " -h prints this help message to STDOUT\n". + " -c preserves upper-case alphabetic characters\n". + " -b generate BLEU scores only\n". + " -n generate NIST scores only\n". + " -d detailed output flag:\n". + " 0 (default) for system-level score only\n". + " 1 to include document-level scores\n". + " 2 to include segment-level scores\n". + " 3 to include ngram-level scores\n". + " -e enclose non-ASCII characters between spaces\n". + " --brevity-penalty ( closest | shortest )\n" . + " closest (default) : acts as IBM BLEU (takes the closest reference translation length)\n" . + " shortest : acts as previous versions of the script (takes the shortest reference translation length)\n" . + " --international-tokenization\n" . + " when specified, uses Unicode-based (only) tokenization rules\n" . + " when not specified (default), uses default tokenization (some language-dependant rules)\n" . + " --metricsMATR : create three files for both BLEU scores and NIST scores:\n" . + " BLEU-seg.scr and NIST-seg.scr : segment-level scores\n" . + " BLEU-doc.scr and NIST-doc.scr : document-level scores\n" . + " BLEU-sys.scr and NIST-sys.scr : system-level scores\n" . + " --no-smoothing : disable smoothing on BLEU scores\n" . + "\n"; + +use vars qw ($opt_r $opt_s $opt_t $opt_d $opt_h $opt_b $opt_n $opt_c $opt_x $opt_e); +use Getopt::Long; +my $ref_file = ''; +my $src_file = ''; +my $tst_file = ''; +my $detail = 0; +my $help = ''; +my $preserve_case = ''; +my $split_non_ASCII = ''; +my $brevity_penalty = 'closest'; +my $international_tokenization; +my $metricsMATR_output = ''; +my $no_smoothing = ''; +our $opt_x = ''; +our $opt_b = ''; +our $opt_n = ''; +GetOptions( + 'r=s' => \$ref_file, + 's=s' => \$src_file, + 't=s' => \$tst_file, + 'd:i' => \$detail, + 'h|help' => \$help, + 'b', + 'n', + 'c' => \$preserve_case, + 'x:s', + 'e' => \$split_non_ASCII, + 'brevity-penalty:s' => \$brevity_penalty, + 'international-tokenization' => \$international_tokenization, + 'metricsMATR-output' => \$metricsMATR_output, + 'no-smoothing' => \$no_smoothing +); +die $usage if $help; + +die "Error in command line: ref_file not defined$usage" unless ( $ref_file ); +die "Error in command line: src_file not defined$usage" unless ( $src_file ); +die "Error in command line: tst_file not defined$usage" unless ( $tst_file ); +my $BLEU_BP; +if ( !( $brevity_penalty cmp 'closest' ) ) +{ + $BLEU_BP = \&brevity_penalty_closest; +} +elsif ( !( $brevity_penalty cmp 'shortest' ) ) +{ + $BLEU_BP = \&brevity_penalty_shortest; +} +else +{ + die "Incorrect value supplied for 'brevity_penalty'$usage"; +} +my $TOKENIZATION = \&tokenization; +$TOKENIZATION = \&tokenization_international if ( $international_tokenization ); + +my $BLEU_SCORE = \&bleu_score; +$BLEU_SCORE = \&bleu_score_nosmoothing if ( $no_smoothing ); + +my $max_Ngram = 9; + +my $METHOD = "BOTH"; +if ( $opt_b ) { $METHOD = "BLEU"; } +if ( $opt_n ) { $METHOD = "NIST"; } +my $method; + +###### +# Global variables +my ($src_lang, $tgt_lang, @tst_sys, @ref_sys); # evaluation parameters +my (%tst_data, %ref_data); # the data -- with structure: {system}{document}{segments} +my ($src_id, $ref_id, $tst_id); # unique identifiers for ref and tst translation sets +my %eval_docs; # document information for the evaluation data set +my %ngram_info; # the information obtained from (the last word in) the ngram + +###### +# Get source document ID's +($src_id) = get_source_info ($src_file); + +###### +# Get reference translations +($ref_id) = get_MT_data (\%ref_data, "RefSet", $ref_file); + +compute_ngram_info (); + +###### +# Get translations to evaluate +($tst_id) = get_MT_data (\%tst_data, "TstSet", $tst_file); + +###### +# Check data for completeness and correctness +check_MT_data (); + +###### +# +my %NISTmt; +my %NISTOverall; +my %BLEUmt; +my %BLEUOverall; + +###### +# Evaluate +print "\nEvaluation of $src_lang-to-$tgt_lang translation using:\n"; +my $cum_seg = 0; +foreach my $doc (sort keys %eval_docs) +{ + $cum_seg += scalar( keys( %{$eval_docs{$doc}{SEGS}} ) ); +} +print " src set \"$src_id\" (", scalar keys %eval_docs, " docs, $cum_seg segs)\n"; +print " ref set \"$ref_id\" (", scalar keys %ref_data, " refs)\n"; +print " tst set \"$tst_id\" (", scalar keys %tst_data, " systems)\n\n"; + +foreach my $sys (sort @tst_sys) +{ + for (my $n=1; $n<=$max_Ngram; $n++) + { + $NISTmt{$n}{$sys}{cum} = 0; + $NISTmt{$n}{$sys}{ind} = 0; + $BLEUmt{$n}{$sys}{cum} = 0; + $BLEUmt{$n}{$sys}{ind} = 0; + } + if ( ($METHOD eq "BOTH") || ($METHOD eq "NIST") ) + { + $method="NIST"; + score_system ($sys, \%NISTmt, \%NISTOverall); + } + if ( ($METHOD eq "BOTH") || ($METHOD eq "BLEU") ) + { + $method="BLEU"; + score_system ($sys, \%BLEUmt, \%BLEUOverall); + } +} + +###### +printout_report (); +if ( $metricsMATR_output ) +{ + outputMetricsMATR( 'NIST', %NISTOverall ) if ( ( $METHOD eq 'BOTH' ) || ( $METHOD eq 'NIST' ) ); + outputMetricsMATR( 'BLEU', %BLEUOverall ) if ( ( $METHOD eq 'BOTH' ) || ( $METHOD eq 'BLEU' ) ); +} + +($date, $time) = date_time_stamp(); +print "\nMT evaluation scorer ended on $date at $time\n"; + +exit 0; + +################################# + +sub get_source_info +{ + my ($file) = @_; + my ($name, $id, $src, $doc, $seg); + my ($data, $tag, $span); + + # Extension of the file determines the parser used: + # .xml : XML::Twig + # otherwise : simple SGML parsing functions + if ( $file =~ /\.xml$/i ) + { + my $twig = XML::Twig->new(); + $twig->parsefile( $file ); + my $root = $twig->root; + my $currentSet = $root->first_child( 'srcset' ); + die "Source XML file '$file' does not contain the 'srcset' element" if ( not $currentSet ); + $id = $currentSet->{ 'att' }->{ 'setid' } or die "No 'setid' attribute value in '$file'"; + $src = $currentSet->{ 'att' }->{ 'srclang' } or die "No srcset 'srclang' attribute value in '$file'"; + die "Not the same srclang attribute values across sets" unless ( not defined $src_lang or $src eq $src_lang ); + $src_lang = $src; + foreach my $currentDoc ( $currentSet->get_xpath( './/doc' ) ) + { + my $docID = $currentDoc->{ 'att' }->{ 'docid' } or die "No document 'docid' attribute value in '$file'"; + foreach my $currentSeg ( $currentDoc->get_xpath( './/seg' ) ) + { + + my $segID = $currentSeg->{ 'att' }->{ 'id' }; + die "No segment 'id' attribute value in '$file'" if (! defined $segID); + my $segData = $currentSeg->text; + ($eval_docs{$docID}{SEGS}{$segID}) = &{ $TOKENIZATION }( $segData ); + } + } + } + else + { + #read data from file + open (FILE, $file) or die "\nUnable to open translation data file '$file'", $usage; + binmode FILE, ":utf8"; + $data .= $_ while <FILE>; + close (FILE); + + #get source set info + die "\n\nFATAL INPUT ERROR: no 'src_set' tag in src_file '$file'\n\n" + unless ($tag, $span, $data) = extract_sgml_tag_and_span ("SrcSet", $data); + die "\n\nFATAL INPUT ERROR: no tag attribute '$name' in file '$file'\n\n" + unless ($id) = extract_sgml_tag_attribute ($name="SetID", $tag); + die "\n\nFATAL INPUT ERROR: no tag attribute '$name' in file '$file'\n\n" + unless ($src) = extract_sgml_tag_attribute ($name="SrcLang", $tag); + die "\n\nFATAL INPUT ERROR: $name ('$src') in file '$file' inconsistent\n" + ." with $name in previous input data ('$src_lang')\n\n" + unless (not defined $src_lang or $src eq $src_lang); + $src_lang = $src; + + #get doc info -- ID and # of segs + $data = $span; + while (($tag, $span, $data) = extract_sgml_tag_and_span ("Doc", $data)) + { + die "\n\nFATAL INPUT ERROR: no tag attribute '$name' in file '$file'\n\n" + unless ($doc) = extract_sgml_tag_attribute ($name="DocID", $tag); + die "\n\nFATAL INPUT ERROR: duplicate '$name' in file '$file'\n\n" + if defined $eval_docs{$doc}; + $span =~ s/[\s\n\r]+/ /g; # concatenate records + my $nseg=0, my $seg_data = $span; + while (($tag, $span, $seg_data) = extract_sgml_tag_and_span ("Seg", $seg_data)) + { + die "\n\nFATAL INPUT ERROR: no attribute '$name' in file '$file'\n\n" + unless ($seg) = extract_sgml_tag_attribute( $name='id', $tag ); + ($eval_docs{$doc}{SEGS}{$seg}) = &{ $TOKENIZATION }( $span ); + $nseg++; + } + die "\n\nFATAL INPUT ERROR: no segments in document '$doc' in file '$file'\n\n" + if $nseg == 0; + } + die "\n\nFATAL INPUT ERROR: no documents in file '$file'\n\n" + unless keys %eval_docs > 0; + } + return $id; +} + +################################# + +sub get_MT_data +{ + my ($docs, $set_tag, $file) = @_; + my ($name, $id, $src, $tgt, $sys, $doc, $seg); + my ($tag, $span, $data); + + # Extension of the file determines the parser used: + # .xml : XML::Twig + # otherwise : simple SGML parsing functions + if ( $file =~ /\.xml$/i ) + { + my $twig = XML::Twig->new(); + $twig->parsefile( $file ); + my $root = $twig->root; + foreach my $currentSet ( $root->get_xpath( 'refset' ), $root->get_xpath( 'tstset' ) ) + { + $id = $currentSet->{ 'att' }->{ 'setid' } or die "No 'setid' attribute value in '$file'"; + $src = $currentSet->{ 'att' }->{ 'srclang' } or die "No 'srclang' attribute value in '$file'"; + $tgt = $currentSet->{ 'att' }->{ 'trglang' } or die "No 'trglang' attribute value in '$file'"; + die "Not the same 'srclang' attribute value across sets" unless ( $src eq $src_lang ); + die "Not the same 'trglang' attribute value across sets" unless ( ( not defined $tgt_lang ) or ( $tgt = $tgt_lang ) ); + $tgt_lang = $tgt; + my $sys; + if ( $currentSet->name eq 'tstset' ) + { + $sys = $currentSet->{ 'att' }->{ 'sysid' } or die "No 'sysid' attribute value in '$file'"; + } + else + { + $sys = $currentSet->{ 'att' }->{ 'refid' } or die "No 'refid' attribute value in '$file'"; + } + foreach my $currentDoc ( $currentSet->get_xpath( './/doc' ) ) + { + my $docID = $currentDoc->{ 'att' }->{ 'docid' } or die "No document 'docid' attribute value in '$file'"; + $docs->{ $sys }{ $docID }{ FILE } = $file; + foreach my $currentSeg ( $currentDoc->get_xpath( './/seg' ) ) + { + my $segID = $currentSeg->{ 'att' }->{ 'id' }; + die "No segment 'id' attribute value in '$file'" if (! defined $segID); + my $segData = $currentSeg->text; + ($docs->{$sys}{$docID}{SEGS}{$segID}) = &{ $TOKENIZATION }( $segData ); + } + } + } + } + else + { + #read data from file + open (FILE, $file) or die "\nUnable to open translation data file '$file'", $usage; + binmode FILE, ":utf8"; + $data .= $_ while <FILE>; + close (FILE); + + #get tag info + while (($tag, $span, $data) = extract_sgml_tag_and_span ($set_tag, $data)) + { + die "\n\nFATAL INPUT ERROR: no tag attribute '$name' in file '$file'\n\n" + unless ($id) = extract_sgml_tag_attribute ($name="SetID", $tag); + die "\n\nFATAL INPUT ERROR: no tag attribute '$name' in file '$file'\n\n" + unless ($src) = extract_sgml_tag_attribute ($name="SrcLang", $tag); + die "\n\nFATAL INPUT ERROR: $name ('$src') in file '$file' inconsistent\n" + ." with $name of source ('$src_lang')\n\n" + unless $src eq $src_lang; + die "\n\nFATAL INPUT ERROR: no tag attribute '$name' in file '$file'\n\n" + unless ($tgt) = extract_sgml_tag_attribute ($name="TrgLang", $tag); + die "\n\nFATAL INPUT ERROR: $name ('$tgt') in file '$file' inconsistent\n" + ." with $name of the evaluation ('$tgt_lang')\n\n" + unless (not defined $tgt_lang or $tgt eq $tgt_lang); + $tgt_lang = $tgt; + + my $mtdata = $span; + while (($tag, $span, $mtdata) = extract_sgml_tag_and_span ("Doc", $mtdata)) + { + die "\n\nFATAL INPUT ERROR: no tag attribute '$name' in file '$file'\n\n" + unless (my $sys) = extract_sgml_tag_attribute ($name="SysID", $tag); + die "\n\nFATAL INPUT ERROR: no tag attribute '$name' in file '$file'\n\n" + unless $doc = extract_sgml_tag_attribute ($name="DocID", $tag); + die "\n\nFATAL INPUT ERROR: document '$doc' for system '$sys' in file '$file'\n" + ." previously loaded from file '$docs->{$sys}{$doc}{FILE}'\n\n" + unless (not defined $docs->{$sys}{$doc}); + + $span =~ s/[\s\n\r]+/ /g; # concatenate records + my $nseg=0, my $seg_data = $span; + while (($tag, $span, $seg_data) = extract_sgml_tag_and_span ("Seg", $seg_data)) + { + die "\n\nFATAIL INPUT ERROR: no tag attribute '$name' in file '$file'\n\n" + unless $seg = extract_sgml_tag_attribute( $name="id", $tag ); + ($docs->{$sys}{$doc}{SEGS}{$seg}) = &{ $TOKENIZATION }( $span ); + $nseg++; + } + die "\n\nFATAL INPUT ERROR: no segments in document '$doc' in file '$file'\n\n" if $nseg == 0; + $docs->{$sys}{$doc}{FILE} = $file; + } + } + } + return $id; +} + +################################# + +sub check_MT_data +{ + @tst_sys = sort keys %tst_data; + @ref_sys = sort keys %ref_data; + + die "Not the same 'setid' attribute values across files" unless ( ( $src_id eq $tst_id ) && ( $src_id eq $ref_id ) ); + +#every evaluation document must be represented for every system and every reference + foreach my $doc (sort keys %eval_docs) + { + my $nseg_source = scalar( keys( %{$eval_docs{$doc}{SEGS}} ) ); + foreach my $sys (@tst_sys) + { + die "\n\nFATAL ERROR: no document '$doc' for system '$sys'\n\n" unless defined $tst_data{$sys}{$doc}; + my $nseg = scalar( keys( %{$tst_data{$sys}{$doc}{SEGS}} ) ); + die "\n\nFATAL ERROR: translated documents must contain the same # of segments as the source, but\n" + ." document '$doc' for system '$sys' contains $nseg segments, while\n" + ." the source document contains $nseg_source segments.\n\n" + unless $nseg == $nseg_source; + } + foreach my $sys (@ref_sys) + { + die "\n\nFATAL ERROR: no document '$doc' for reference '$sys'\n\n" unless defined $ref_data{$sys}{$doc}; + my $nseg = scalar( keys( %{$ref_data{$sys}{$doc}{SEGS}} ) ); + die "\n\nFATAL ERROR: translated documents must contain the same # of segments as the source, but\n" + ." document '$doc' for system '$sys' contains $nseg segments, while\n" + ." the source document contains $nseg_source segments.\n\n" + unless $nseg == $nseg_source; + } + } +} + +################################# + +sub compute_ngram_info +{ + my ($ref, $doc, $seg); + my (@wrds, $tot_wrds, %ngrams, $ngram, $mgram); + my (%ngram_count, @tot_ngrams); + + foreach $ref (keys %ref_data) + { + foreach $doc (keys %{$ref_data{$ref}}) + { + foreach $seg ( keys %{$ref_data{$ref}{$doc}{SEGS}}) + { + @wrds = split /\s+/, $ref_data{ $ref }{ $doc }{ SEGS }{ $seg }; + $tot_wrds += @wrds; + %ngrams = %{Words2Ngrams (@wrds)}; + foreach $ngram (keys %ngrams) + { + $ngram_count{$ngram} += $ngrams{$ngram}; + } + } + } + } + + foreach $ngram (keys %ngram_count) + { + @wrds = split / /, $ngram; + pop @wrds, $mgram = join " ", @wrds; + $ngram_info{$ngram} = - log ($mgram ? $ngram_count{$ngram}/$ngram_count{$mgram} : $ngram_count{$ngram}/$tot_wrds) / log 2; + if (defined $opt_x and $opt_x eq "ngram info") + { + @wrds = split / /, $ngram; + printf "ngram info:%9.4f%6d%6d%8d%3d %s\n", $ngram_info{$ngram}, $ngram_count{$ngram}, + $mgram ? $ngram_count{$mgram} : $tot_wrds, $tot_wrds, scalar @wrds, $ngram; + } + } +} + +################################# + +sub score_system +{ + my ($sys, $ref, $doc, $SCOREmt, $overallScore); + ($sys, $SCOREmt, $overallScore) = @_; + my ($ref_length, $match_cnt, $tst_cnt, $ref_cnt, $tst_info, $ref_info); + my ($cum_ref_length, @cum_match, @cum_tst_cnt, @cum_ref_cnt, @cum_tst_info, @cum_ref_info); + + $cum_ref_length = 0; + for (my $j=1; $j<=$max_Ngram; $j++) + { + $cum_match[$j] = $cum_tst_cnt[$j] = $cum_ref_cnt[$j] = $cum_tst_info[$j] = $cum_ref_info[$j] = 0; + } + foreach $doc (sort keys %eval_docs) + { + ($ref_length, $match_cnt, $tst_cnt, $ref_cnt, $tst_info, $ref_info) = score_document ($sys, $doc, $overallScore); + if ( $method eq "NIST" ) + { + my %DOCmt = (); + my $docScore = nist_score( scalar( @ref_sys ), $match_cnt, $tst_cnt, $ref_cnt, $tst_info, $ref_info, $sys, \%DOCmt ); + $overallScore->{ $sys }{ 'documents' }{ $doc }{ 'score' } = $docScore; + if ( $detail >= 1 ) + { + printf "$method score using 5-grams = %.4f for system \"$sys\" on document \"$doc\" (%d segments, %d words)\n", + $docScore, scalar keys %{$tst_data{$sys}{$doc}{SEGS}}, $tst_cnt->[1]; + } + } + + if ( $method eq "BLEU" ) + { + my %DOCmt = (); + my $docScore = &{$BLEU_SCORE}( $ref_length, $match_cnt, $tst_cnt, $sys, \%DOCmt ); + $overallScore->{ $sys }{ 'documents' }{ $doc }{ 'score' } = $docScore; + if ( $detail >= 1 ) + { + printf "$method score using 4-grams = %.4f for system \"$sys\" on document \"$doc\" (%d segments, %d words)\n", + $docScore, scalar keys %{$tst_data{$sys}{$doc}{SEGS}}, $tst_cnt->[1]; + } + } + + $cum_ref_length += $ref_length; + for (my $j=1; $j<=$max_Ngram; $j++) + { + $cum_match[$j] += $match_cnt->[$j]; + $cum_tst_cnt[$j] += $tst_cnt->[$j]; + $cum_ref_cnt[$j] += $ref_cnt->[$j]; + $cum_tst_info[$j] += $tst_info->[$j]; + $cum_ref_info[$j] += $ref_info->[$j]; + printf "document info: $sys $doc %d-gram %d %d %d %9.4f %9.4f\n", $j, $match_cnt->[$j], + $tst_cnt->[$j], $ref_cnt->[$j], $tst_info->[$j], $ref_info->[$j] + if (defined $opt_x and $opt_x eq "document info"); + } + } + + if ($method eq "BLEU") + { + $overallScore->{ $sys }{ 'score' } = &{$BLEU_SCORE}($cum_ref_length, \@cum_match, \@cum_tst_cnt, $sys, $SCOREmt); + } + if ($method eq "NIST") + { + $overallScore->{ $sys }{ 'score' } = nist_score (scalar @ref_sys, \@cum_match, \@cum_tst_cnt, \@cum_ref_cnt, \@cum_tst_info, \@cum_ref_info, $sys, $SCOREmt); + } +} + +################################# + +sub score_document +{ + my ($sys, $ref, $doc, $overallScore); + ($sys, $doc, $overallScore) = @_; + my ($ref_length, $match_cnt, $tst_cnt, $ref_cnt, $tst_info, $ref_info); + my ($cum_ref_length, @cum_match, @cum_tst_cnt, @cum_ref_cnt, @cum_tst_info, @cum_ref_info); + + $cum_ref_length = 0; + for (my $j=1; $j<=$max_Ngram; $j++) + { + $cum_match[$j] = $cum_tst_cnt[$j] = $cum_ref_cnt[$j] = $cum_tst_info[$j] = $cum_ref_info[$j] = 0; + } + + # score each segment + foreach my $seg ( nsort keys( %{$tst_data{$sys}{$doc}{SEGS}} ) ) + { + + my @ref_segments = (); + foreach $ref (@ref_sys) + { + push @ref_segments, $ref_data{$ref}{$doc}{SEGS}{$seg}; + if ( $detail >= 3 ) + { + printf "ref '$ref', seg $seg: %s\n", $ref_data{$ref}{$doc}{SEGS}{$seg} + } + + } + + printf "sys '$sys', seg $seg: %s\n", $tst_data{$sys}{$doc}{SEGS}{$seg} if ( $detail >= 3 ); + ($ref_length, $match_cnt, $tst_cnt, $ref_cnt, $tst_info, $ref_info) = score_segment ($tst_data{$sys}{$doc}{SEGS}{$seg}, @ref_segments); + + if ( $method eq "BLEU" ) + { + my %DOCmt = (); + my $segScore = &{$BLEU_SCORE}($ref_length, $match_cnt, $tst_cnt, $sys, %DOCmt); + $overallScore->{ $sys }{ 'documents' }{ $doc }{ 'segments' }{ $seg }{ 'score' } = $segScore; + if ( $detail >= 2 ) + { + printf " $method score using 4-grams = %.4f for system \"$sys\" on segment $seg of document \"$doc\" (%d words)\n", $segScore, $tst_cnt->[1] + } + } + if ( $method eq "NIST" ) + { + my %DOCmt = (); + my $segScore = nist_score (scalar @ref_sys, $match_cnt, $tst_cnt, $ref_cnt, $tst_info, $ref_info, $sys, %DOCmt); + $overallScore->{ $sys }{ 'documents' }{ $doc }{ 'segments' }{ $seg }{ 'score' } = $segScore; + if ( $detail >= 2 ) + { + printf " $method score using 5-grams = %.4f for system \"$sys\" on segment $seg of document \"$doc\" (%d words)\n", $segScore, $tst_cnt->[1]; + } + } + $cum_ref_length += $ref_length; + for (my $j=1; $j<=$max_Ngram; $j++) + { + $cum_match[$j] += $match_cnt->[$j]; + $cum_tst_cnt[$j] += $tst_cnt->[$j]; + $cum_ref_cnt[$j] += $ref_cnt->[$j]; + $cum_tst_info[$j] += $tst_info->[$j]; + $cum_ref_info[$j] += $ref_info->[$j]; + } + } + return ($cum_ref_length, [@cum_match], [@cum_tst_cnt], [@cum_ref_cnt], [@cum_tst_info], [@cum_ref_info]); +} + +############################################################################################################################### +# function returning the shortest reference length +# takes as input: +# - currentLength : the current (shortest) reference length +# - referenceSentenceLength : the current reference sentence length +# - candidateSentenceLength : the current candidate sentence length (unused) +############################################################################################################################### +sub brevity_penalty_shortest +{ + my ( $currentLength, $referenceSentenceLength, $candidateSentenceLength ) = @_; + return ( $referenceSentenceLength < $currentLength ? $referenceSentenceLength : $currentLength ); +} + +############################################################################################################################### +# function returning the closest reference length (to the candidate sentence length) +# takes as input: +# - currentLength: the current (closest) reference length. +# - candidateSentenceLength : the current reference sentence length +# - candidateSentenceLength : the current candidate sentence length +# when two reference sentences are at the same distance, it will return the shortest reference sentence length +# example of 4 iterations, given: +# - one candidate sentence containing 7 tokens +# - one reference translation containing 11 tokens +# - one reference translation containing 8 tokens +# - one reference translation containing 6 tokens +# - one reference translation containing 7 tokens +# the multiple invokations will return: +# - currentLength is set to 11 (outside of this function) +# - brevity_penalty_closest( 11, 8, 7 ) returns 8, since abs( 8 - 7 ) < abs( 11 - 7 ) +# - brevity_penalty_closest( 8, 6, 7 ) returns 6, since abs( 8 - 7 ) == abs( 6 - 7 ) AND 6 < 8 +# - brevity_penalty_closest( 7, 6, 7 ) returns 7, since abs( 7 - 7 ) < abs( 6 - 7 ) +############################################################################################################################### +sub brevity_penalty_closest +{ + my ( $currentLength, $referenceSentenceLength, $candidateSentenceLength ) = @_; + my $result = $currentLength; + if ( abs( $candidateSentenceLength - $referenceSentenceLength ) <= abs( $candidateSentenceLength - $currentLength ) ) + { + if ( abs( $candidateSentenceLength - $referenceSentenceLength ) == abs( $candidateSentenceLength - $currentLength ) ) + { + if ( $currentLength > $referenceSentenceLength ) + { + $result = $referenceSentenceLength; + } + } + else + { + $result = $referenceSentenceLength; + } + } + return $result; +} + +################################# + +sub score_segment +{ + my ($tst_seg, @ref_segs) = @_; + my (@tst_wrds, %tst_ngrams, @match_count, @tst_count, @tst_info); + my (@ref_wrds, $ref_seg, %ref_ngrams, %ref_ngrams_max, @ref_count, @ref_info); + my ($ngram); + my (@nwrds_ref); + my $ref_length; + + for (my $j=1; $j<= $max_Ngram; $j++) + { + $match_count[$j] = $tst_count[$j] = $ref_count[$j] = $tst_info[$j] = $ref_info[$j] = 0; + } + +# get the ngram counts for the test segment + @tst_wrds = split /\s+/, $tst_seg; + %tst_ngrams = %{Words2Ngrams (@tst_wrds)}; + for (my $j=1; $j<=$max_Ngram; $j++) + { + # compute ngram counts + $tst_count[$j] = $j<=@tst_wrds ? (@tst_wrds - $j + 1) : 0; + } + +# get the ngram counts for the reference segments + foreach $ref_seg (@ref_segs) + { + @ref_wrds = split /\s+/, $ref_seg; + %ref_ngrams = %{Words2Ngrams (@ref_wrds)}; + foreach $ngram (keys %ref_ngrams) + { + # find the maximum # of occurrences + my @wrds = split / /, $ngram; + $ref_info[@wrds] += $ngram_info{$ngram}; + $ref_ngrams_max{$ngram} = defined $ref_ngrams_max{$ngram} ? max ($ref_ngrams_max{$ngram}, $ref_ngrams{$ngram}) : $ref_ngrams{$ngram}; + } + for (my $j=1; $j<=$max_Ngram; $j++) + { + # update ngram counts + $ref_count[$j] += $j<=@ref_wrds ? (@ref_wrds - $j + 1) : 0; + } + if ( not defined( $ref_length ) ) + { + $ref_length = scalar( @ref_wrds ); + } + else + { + $ref_length = &{$BLEU_BP}( $ref_length, scalar( @ref_wrds ), scalar( @tst_wrds ) ); + } + } + +# accumulate scoring stats for tst_seg ngrams that match ref_seg ngrams + foreach $ngram (keys %tst_ngrams) + { + next unless defined $ref_ngrams_max{$ngram}; + my @wrds = split / /, $ngram; + $tst_info[@wrds] += $ngram_info{$ngram} * min($tst_ngrams{$ngram},$ref_ngrams_max{$ngram}); + $match_count[@wrds] += my $count = min($tst_ngrams{$ngram},$ref_ngrams_max{$ngram}); + printf "%.2f info for each of $count %d-grams = '%s'\n", $ngram_info{$ngram}, scalar @wrds, $ngram + if $detail >= 3; + } + + return ($ref_length, [@match_count], [@tst_count], [@ref_count], [@tst_info], [@ref_info]); +} + +################################# + +sub bleu_score_nosmoothing +{ + my ($ref_length, $matching_ngrams, $tst_ngrams, $sys, $SCOREmt) = @_; + my $score = 0; + my $iscore = 0; + + for ( my $j = 1; $j <= $max_Ngram; ++$j ) + { + if ($matching_ngrams->[ $j ] == 0) + { + $SCOREmt->{ $j }{ $sys }{ cum }=0; + } + else + { + my $len_score = min (0, 1-$ref_length/$tst_ngrams->[1]); + # Cumulative N-Gram score + $score += log( $matching_ngrams->[ $j ] / $tst_ngrams->[ $j ] ); + $SCOREmt->{ $j }{ $sys }{ cum } = exp( $score / $j + $len_score ); + # Individual N-Gram score + $iscore = log( $matching_ngrams->[ $j ] / $tst_ngrams->[ $j ] ); + $SCOREmt->{ $j }{ $sys }{ ind } = exp( $iscore ); + } + } + return $SCOREmt->{ 4 }{ $sys }{ cum }; +} + +############################################################################################################################### +# Default method used to compute the BLEU score, using smoothing. +# Note that the method used can be overridden using the '--no-smoothing' command-line argument +# The smoothing is computed by taking 1 / ( 2^k ), instead of 0, for each precision score whose matching n-gram count is null +# k is 1 for the first 'n' value for which the n-gram match count is null +# For example, if the text contains: +# - one 2-gram match +# - and (consequently) two 1-gram matches +# the n-gram count for each individual precision score would be: +# - n=1 => prec_count = 2 (two unigrams) +# - n=2 => prec_count = 1 (one bigram) +# - n=3 => prec_count = 1/2 (no trigram, taking 'smoothed' value of 1 / ( 2^k ), with k=1) +# - n=4 => prec_count = 1/4 (no fourgram, taking 'smoothed' value of 1 / ( 2^k ), with k=2) +############################################################################################################################### +sub bleu_score +{ + my ($ref_length, $matching_ngrams, $tst_ngrams, $sys, $SCOREmt) = @_; + my $score = 0; + my $iscore = 0; + my $exp_len_score = 0; + $exp_len_score = exp( min (0, 1 - $ref_length / $tst_ngrams->[ 1 ] ) ) if ( $tst_ngrams->[ 1 ] > 0 ); + my $smooth = 1; + for ( my $j = 1; $j <= $max_Ngram; ++$j ) + { + if ( $tst_ngrams->[ $j ] == 0 ) + { + $iscore = 0; + } + elsif ( $matching_ngrams->[ $j ] == 0 ) + { + $smooth *= 2; + $iscore = log( 1 / ( $smooth * $tst_ngrams->[ $j ] ) ); + } + else + { + $iscore = log( $matching_ngrams->[ $j ] / $tst_ngrams->[ $j ] ); + } + $SCOREmt->{ $j }{ $sys }{ ind } = exp( $iscore ); + $score += $iscore; + $SCOREmt->{ $j }{ $sys }{ cum } = exp( $score / $j ) * $exp_len_score; + } + return $SCOREmt->{ 4 }{ $sys }{ cum }; +} + +################################# + +sub nist_score +{ + my ($nsys, $matching_ngrams, $tst_ngrams, $ref_ngrams, $tst_info, $ref_info, $sys, $SCOREmt) = @_; + my $score = 0; + my $iscore = 0; + + for (my $n=1; $n<=$max_Ngram; $n++) + { + $score += $tst_info->[$n]/max($tst_ngrams->[$n],1); + $SCOREmt->{$n}{$sys}{cum} = $score * nist_length_penalty($tst_ngrams->[1]/($ref_ngrams->[1]/$nsys)); + $iscore = $tst_info->[$n]/max($tst_ngrams->[$n],1); + $SCOREmt->{$n}{$sys}{ind} = $iscore * nist_length_penalty($tst_ngrams->[1]/($ref_ngrams->[1]/$nsys)); + } + return $SCOREmt->{5}{$sys}{cum}; +} + +################################# + +sub Words2Ngrams +{ + #convert a string of words to an Ngram count hash + my %count = (); + + for (; @_; shift) + { + my ($j, $ngram, $word); + for ($j=0; $j<$max_Ngram and defined($word=$_[$j]); $j++) + { + $ngram .= defined $ngram ? " $word" : $word; + $count{$ngram}++; + } + } + return {%count}; +} + +################################# + +sub tokenization +{ + my ($norm_text) = @_; + +# language-independent part: + $norm_text =~ s/<skipped>//g; # strip "skipped" tags + $norm_text =~ s/-\n//g; # strip end-of-line hyphenation and join lines + $norm_text =~ s/\n/ /g; # join lines + $norm_text =~ s/"/"/g; # convert SGML tag for quote to " + $norm_text =~ s/&/&/g; # convert SGML tag for ampersand to & + $norm_text =~ s/</</g; # convert SGML tag for less-than to > + $norm_text =~ s/>/>/g; # convert SGML tag for greater-than to < + +# language-dependent part (assuming Western languages): + $norm_text = " $norm_text "; + $norm_text =~ tr/[A-Z]/[a-z]/ unless $preserve_case; + $norm_text =~ s/([\{-\~\[-\` -\&\(-\+\:-\@\/])/ $1 /g; # tokenize punctuation + $norm_text =~ s/([^0-9])([\.,])/$1 $2 /g; # tokenize period and comma unless preceded by a digit + $norm_text =~ s/([\.,])([^0-9])/ $1 $2/g; # tokenize period and comma unless followed by a digit + $norm_text =~ s/([0-9])(-)/$1 $2 /g; # tokenize dash when preceded by a digit + $norm_text =~ s/\s+/ /g; # one space only between words + $norm_text =~ s/^\s+//; # no leading space + $norm_text =~ s/\s+$//; # no trailing space + + return $norm_text; +} + + +sub tokenization_international +{ + my ($norm_text) = @_; + + $norm_text =~ s/<skipped>//g; # strip "skipped" tags + #$norm_text =~ s/\p{Hyphen}\p{Zl}//g; # strip end-of-line hyphenation and join lines + $norm_text =~ s/\p{Zl}/ /g; # join lines + + # replace entities + $norm_text =~ s/"/\"/g; # quote to " + $norm_text =~ s/&/&/g; # ampersand to & + $norm_text =~ s/</</g; # less-than to < + $norm_text =~ s/>/>/g; # greater-than to > + $norm_text =~ s/'/\'/g; # apostrophe to ' + + $norm_text = lc( $norm_text ) unless $preserve_case; # lowercasing if needed + $norm_text =~ s/([^[:ascii:]])/ $1 /g if ( $split_non_ASCII ); + + # punctuation: tokenize any punctuation unless followed AND preceded by a digit + $norm_text =~ s/(\P{N})(\p{P})/$1 $2 /g; + $norm_text =~ s/(\p{P})(\P{N})/ $1 $2/g; + + $norm_text =~ s/(\p{S})/ $1 /g; # tokenize symbols + + $norm_text =~ s/\p{Z}+/ /g; # one space only between words + $norm_text =~ s/^\p{Z}+//; # no leading space + $norm_text =~ s/\p{Z}+$//; # no trailing space + + return $norm_text; +} + +################################# + +sub nist_length_penalty +{ + my ($ratio) = @_; + return 1 if $ratio >= 1; + return 0 if $ratio <= 0; + my $ratio_x = 1.5; + my $score_x = 0.5; + my $beta = -log($score_x)/log($ratio_x)/log($ratio_x); + return exp (-$beta*log($ratio)*log($ratio)); +} + +################################# + +sub date_time_stamp +{ + my ($sec, $min, $hour, $mday, $mon, $year, $wday, $yday, $isdst) = localtime(); + my @months = qw(Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec); + my ($date, $time); + $time = sprintf "%2.2d:%2.2d:%2.2d", $hour, $min, $sec; + $date = sprintf "%4.4s %3.3s %s", 1900+$year, $months[$mon], $mday; + return ($date, $time); +} + +################################# + +sub extract_sgml_tag_and_span +{ + my ($name, $data) = @_; + ($data =~ m|<$name\s*([^>]*)>(.*?)</$name\s*>(.*)|si) ? ($1, $2, $3) : (); +} + +################################# + +sub extract_sgml_tag_attribute +{ + my ($name, $data) = @_; + ($data =~ m|$name\s*=\s*\"([^\"]*)\"|si) ? ($1) : (); +} + +################################# + +sub max +{ + my ($max, $next); + + return unless defined ($max=pop); + while (defined ($next=pop)) + { + $max = $next if $next > $max; + } + return $max; +} + +################################# + +sub min +{ + my ($min, $next); + + return unless defined ($min=pop); + while (defined ($next=pop)) + { + $min = $next if $next < $min; + } + return $min; +} + +################################# + +sub printout_report +{ + if ( $METHOD eq "BOTH" ) + { + foreach my $sys (sort @tst_sys) + { + printf "NIST score = %2.4f BLEU score = %.4f for system \"$sys\"\n",$NISTmt{5}{$sys}{cum},$BLEUmt{4}{$sys}{cum}; + } + } + elsif ($METHOD eq "NIST" ) + { + foreach my $sys (sort @tst_sys) + { + printf "NIST score = %2.4f for system \"$sys\"\n",$NISTmt{5}{$sys}{cum}; + } + } + elsif ($METHOD eq "BLEU" ) + { + foreach my $sys (sort @tst_sys) + { + printf "\nBLEU score = %.4f for system \"$sys\"\n",$BLEUmt{4}{$sys}{cum}; + } + } + printf "\n# ------------------------------------------------------------------------\n\n"; + printf "Individual N-gram scoring\n"; + printf " 1-gram 2-gram 3-gram 4-gram 5-gram 6-gram 7-gram 8-gram 9-gram\n"; + printf " ------ ------ ------ ------ ------ ------ ------ ------ ------\n"; + + if ( ( $METHOD eq "BOTH" ) || ($METHOD eq "NIST") ) + { + foreach my $sys (sort @tst_sys) + { + printf " NIST:"; + for (my $i=1; $i<=$max_Ngram; $i++) + { + printf " %2.4f ",$NISTmt{$i}{$sys}{ind} + } + printf " \"$sys\"\n"; + } + printf "\n"; + } + + if ( ( $METHOD eq "BOTH" ) || ($METHOD eq "BLEU") ) + { + foreach my $sys (sort @tst_sys) + { + printf " BLEU:"; + for (my $i=1; $i<=$max_Ngram; $i++) + { + printf " %2.4f ",$BLEUmt{$i}{$sys}{ind} + } + printf " \"$sys\"\n"; + } + } + + printf "\n# ------------------------------------------------------------------------\n"; + printf "\nCumulative N-gram scoring\n"; + printf " 1-gram 2-gram 3-gram 4-gram 5-gram 6-gram 7-gram 8-gram 9-gram\n"; + printf " ------ ------ ------ ------ ------ ------ ------ ------ ------\n"; + + if (( $METHOD eq "BOTH" ) || ($METHOD eq "NIST")) + { + foreach my $sys (sort @tst_sys) + { + printf " NIST:"; + for (my $i=1; $i<=$max_Ngram; $i++) + { + printf " %2.4f ",$NISTmt{$i}{$sys}{cum} + } + printf " \"$sys\"\n"; + } + } + printf "\n"; + if ( ( $METHOD eq "BOTH" ) || ($METHOD eq "BLEU") ) + { + foreach my $sys (sort @tst_sys) + { + printf " BLEU:"; + for (my $i=1; $i<=$max_Ngram; $i++) + { + printf " %2.4f ",$BLEUmt{$i}{$sys}{cum} + } + printf " \"$sys\"\n"; + } + } +} + +############################################################################################################################### +# Create three files, by using: +# - $prefix : the prefix used for the output file names +# - %overall : a hash containing seg/doc/sys-level scores: +# - $overall{ $SYSTEM_ID }{ 'score' } => system-level score +# - $overall{ $SYSTEM_ID }{ 'documents' }{ $DOCUMENT_ID }{ 'score' } => document-level score +# - $overall{ $SYSTEM_ID }{ 'documents' }{ $DOCUMENT_ID }{ 'segments' }{ $SEGMENT_ID } => segment-level score +############################################################################################################################### +sub outputMetricsMATR +{ + my ( $prefix, %overall ) = @_; + my $fileNameSys = $prefix . '-sys.scr'; + my $fileNameDoc = $prefix . '-doc.scr'; + my $fileNameSeg = $prefix . '-seg.scr'; + open FILEOUT_SYS, '>', $fileNameSys or die "Could not open file: ${fileNameSys}"; + open FILEOUT_DOC, '>', $fileNameDoc or die "Could not open file: ${fileNameDoc}"; + open FILEOUT_SEG, '>', $fileNameSeg or die "Could not open file: ${fileNameSeg}"; + foreach my $sys ( sort( keys( %overall ) ) ) + { + my $scoreSys = $overall{ $sys }{ 'score' }; + print FILEOUT_SYS "${tst_id}\t${sys}\t${scoreSys}\n"; + foreach my $doc ( sort( keys( %{$overall{ $sys }{ 'documents' }} ) ) ) + { + my $scoreDoc = $overall{ $sys }{ 'documents' }{ $doc }{ 'score' }; + print FILEOUT_DOC "${tst_id}\t${sys}\t${doc}\t${scoreDoc}\n"; + foreach my $seg ( nsort keys( %{$overall{ $sys }{ 'documents' }{ $doc }{ 'segments' }} ) ) + { + my $scoreSeg = $overall{ $sys }{ 'documents' }{ $doc }{ 'segments' }{ $seg }{ 'score' }; + print FILEOUT_SEG "${tst_id}\t${sys}\t${doc}\t${seg}\t${scoreSeg}\n"; + } + } + } + close FILEOUT_SEG; + close FILEOUT_DOC; + close FILEOUT_SYS; +} + |