package edu.northwestern.at.morphadorner.tools.createsuffixlexicon;
/* Please see the license information at the end of this file. */
import java.awt.*;
import java.awt.event.*;
import java.io.*;
import java.util.*;
import edu.northwestern.at.utils.*;
import edu.northwestern.at.utils.corpuslinguistics.lexicon.*;
/** Generate suffix lexicon from a word lexicon.
*
* <p>
* <code>
* java -Xmx512m edu.northwestern.at.morphadorner.tools.createsuffixlexicon.CreateSuffixLexicon
* inputwordlexicon outputsuffixlexicon maxsuffixlength maxsuffixcount
* </code>
* </p>
*
* <ul>
* <li>
* <p>
* <strong>inputwordlexicon</strong> specifies the name of the
* input file containng the word lexicon from which to extract
* a suffix lexicon.
* </p>
* </li>
*
* <li>
* <p>
* <strong>outputsuffixlexicon</strong> specifies the name of the
* output file to receive tthe suffix lexicon.
* </p>
* </li>
*
* <li>
* <p>
* <strong>maxsuffixlength</strong> specifies the maximum length
* suffix generated for the suffix lexicon. The default is 6.
* </p>
* </li>
*
* <li>
* <p>
* <strong>maxsuffixcount</strong> specifies the maximum number
* of times a spelling can appear in order for its suffix to be
* added to the suffix lexicon. The default is to include
* all words regardless of count.
* </p>
*
* <p>
* For some applications you may want to restrict the
* suffix lexicon to contain suffixes only for infrequently
* occurring words. Values of 10 (only include spellings which appear
* 10 or less times in the training data) or 1 (only include spellings
* which appear once in the training data) are popular choices.
* </p>
* </li>
* </ul>
*/
public class CreateSuffixLexicon
{
/** Input word lexicon file name. */
protected static String wordLexiconFileName;
/** Output suffix lexicon file name. */
protected static String suffixLexiconFileName;
/** Only use words less than maxSuffixCount to generate
* suffix lexicon.
*
* <p>
* The default is to use all words regardless of word count.
* </p>
*/
protected static int maxSuffixCount = Integer.MAX_VALUE;
/** Maximum and minimum length suffixes to generated.
*/
protected static int maxSuffixLength = 6;
protected static int minSuffixLength = 1;
/** Generate suffix lexicon.
*/
private static void generateSuffixLexicon()
throws IOException
{
long startTime = System.currentTimeMillis();
// Load word lexicon.
BaseLexicon wordLexicon =
new BaseLexicon();
// Load default word lexicon.
wordLexicon.loadLexicon
(
new File( wordLexiconFileName ).toURI().toURL() ,
"utf-8"
);
// Create empty suffix lexicon.
BaseLexicon suffixLexicon = new BaseLexicon();
// Generate suffix lexicon from
// word lexicon. We can't do this
// in parallel with the word lexicon
// creation because we need the
// word counts.
String[] entries = wordLexicon.getEntries();
for ( int i = 0 ; i < entries.length ; i++ )
{
String entry = entries[ i ];
int entryCount = wordLexicon.getEntryCount( entry );
if ( entryCount <= maxSuffixCount )
{
String lowerCaseEntry = entry.toLowerCase();
int l = lowerCaseEntry.length();
Map<String, MutableInteger> categoryCounts =
wordLexicon.getCategoryCountsForEntry( entry );
// Loop over each category for the
// entry.
Iterator<String> iterator =
categoryCounts.keySet().iterator();
while ( iterator.hasNext() )
{
// Get category name and count.
String categoryName = iterator.next();
// Get the category count.
int categoryCount =
categoryCounts.get( categoryName ).intValue();
// Extract suffixes of decreasing length
// and add to suffix lexicon.
for ( int j = maxSuffixLength ;
j > minSuffixLength - 1 ;
j--
)
{
if ( lowerCaseEntry.length() > j )
{
suffixLexicon.updateEntryCount
(
lowerCaseEntry.substring( l - j , l ) ,
categoryName ,
"*" ,
categoryCount
);
}
}
}
}
}
// Output suffix lexicon.
System.out.println(
"Writing suffix lexicon to " + suffixLexiconFileName + " .");
System.out.println(
" Maximum suffix length is " + maxSuffixLength + " .");
if ( maxSuffixCount == Integer.MAX_VALUE )
{
System.out.println(
" Suffixes generated from all spellings." );
}
else
{
System.out.println(
" Suffixes generated from spellings appearing no more than " +
Formatters.formatIntegerWithCommas( maxSuffixCount ) +
" time" + ( maxSuffixCount == 1 ? "" : "s" ) +
"." );
}
suffixLexicon.saveLexiconToTextFile(
suffixLexiconFileName , "utf-8" );
// Report time and statistics for
// creation.
long endTime =
( System.currentTimeMillis() - startTime + 999 ) / 1000;
System.out.println(
"Lexicon generated in " +
Formatters.formatLongWithCommas( endTime ) + " seconds." );
System.out.println(
"Suffix lexicon contains " +
Formatters.formatIntegerWithCommas(
suffixLexicon.getLexiconSize() ) +
" entries." );
wordLexicon.close();
suffixLexicon.close();
}
/** Display brief help.
*/
protected static void help()
{
System.out.println( "Usage: " );
System.out.println( "" );
System.out.println( "java -Xmx512m edu.northwestern.at.createlexicon.CreateSuffixLexicon ^" );
System.out.println( " inputwordlexicon outputsuffixlexicon maxsuffixlength maxsuffixcount" );
System.out.println( "" );
System.out.println( "-- inputwordlexicon specifies the input word lexicon (required)." );
System.out.println( "-- outputsuffixlexicon receives output suffix lexicon (required)." );
System.out.println( "-- maxsuffixlength is maximum length suffix to generate (optional, default is 6)." );
System.out.println( "-- maxsuffixcount is maximum count for spelling to include in suffix lexicon (optional, default is no maximum)." );
}
/** Initialize.
*
* @param args Command line arguments.
*/
protected static boolean initialize( String[] args )
{
boolean result = true;
if ( args.length < 2 )
{
result = false;
help();
}
else
{
wordLexiconFileName = args[ 0 ];
suffixLexiconFileName = args[ 1 ];
if ( args.length > 2 )
{
try
{
maxSuffixLength = Integer.parseInt( args[ 2 ] );
}
catch ( Exception e )
{
result = false;
System.out.println( "Bad maximum suffix length." );
}
}
if ( args.length > 4 )
{
try
{
maxSuffixCount = Integer.parseInt( args[ 3 ] );
}
catch ( Exception e )
{
result = false;
System.out.println( "Bad maximum suffix count." );
}
}
}
return result;
}
/** Main program.
*
* @param args Command line arguments.
*/
public static void main( String args[] )
{
// If initialization succeeds ...
int returnCode = 0;
if ( initialize( args ) )
{
// Generate the lexicons.
try
{
generateSuffixLexicon();
}
catch ( Exception e )
{
e.printStackTrace();
returnCode = 1;
}
}
// Halt with error 1 if any error.
if ( returnCode != 0 )
{
System.exit( returnCode );
}
}
}
/*
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Developed by:
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Northwestern University
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Software is furnished to do so, subject to the following
conditions:
* Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimers.
* Redistributions in binary form must reproduce the above
copyright notice, this list of conditions and the following
disclaimers in the documentation and/or other materials provided
with the distribution.
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