gatk-3.8/java/src/org/broadinstitute/sting/alignment/CountBestAlignmentsWalker.java

93 lines
3.1 KiB
Java

package org.broadinstitute.sting.alignment;
import org.broadinstitute.sting.gatk.walkers.ReadWalker;
import org.broadinstitute.sting.alignment.bwa.BWTFiles;
import org.broadinstitute.sting.alignment.bwa.BWAConfiguration;
import org.broadinstitute.sting.alignment.bwa.c.BWACAligner;
import org.broadinstitute.sting.utils.cmdLine.Argument;
import net.sf.samtools.SAMRecord;
import java.util.*;
/**
* Counts the number of best alignments
*
* @author mhanna
* @version 0.1
*/
public class CountBestAlignmentsWalker extends ReadWalker<Integer,Integer> {
/**
* The supporting BWT index generated using BWT.
*/
@Argument(fullName="BWTPrefix",shortName="BWT",doc="Index files generated by bwa index -d bwtsw",required=false)
private String prefix = null;
/**
* The actual aligner.
*/
private Aligner aligner = null;
private SortedMap<Integer,Integer> alignmentFrequencies = new TreeMap<Integer,Integer>();
/**
* Create an aligner object. The aligner object will load and hold the BWT until close() is called.
*/
@Override
public void initialize() {
if(prefix == null)
prefix = getToolkit().getArguments().referenceFile.getAbsolutePath();
BWTFiles bwtFiles = new BWTFiles(prefix);
BWAConfiguration configuration = new BWAConfiguration();
aligner = new BWACAligner(bwtFiles,configuration);
}
/**
* Aligns a read to the given reference.
* @param ref Reference over the read. Read will most likely be unmapped, so ref will be null.
* @param read Read to align.
* @return Number of alignments found for this read.
*/
@Override
public Integer map(char[] ref, SAMRecord read) {
Iterator<Alignment[]> alignmentIterator = aligner.getAllAlignments(read.getReadBases()).iterator();
if(alignmentIterator.hasNext()) {
int numAlignments = alignmentIterator.next().length;
if(alignmentFrequencies.containsKey(numAlignments))
alignmentFrequencies.put(numAlignments,alignmentFrequencies.get(numAlignments)+1);
else
alignmentFrequencies.put(numAlignments,1);
}
return 1;
}
/**
* Initial value for reduce. In this case, validated reads will be counted.
* @return 0, indicating no reads yet validated.
*/
@Override
public Integer reduceInit() { return 0; }
/**
* Calculates the number of reads processed.
* @param value Number of reads processed by this map.
* @param sum Number of reads processed before this map.
* @return Number of reads processed up to and including this map.
*/
@Override
public Integer reduce(Integer value, Integer sum) {
return value + sum;
}
/**
* Cleanup.
* @param result Number of reads processed.
*/
@Override
public void onTraversalDone(Integer result) {
aligner.close();
for(Map.Entry<Integer,Integer> alignmentFrequency: alignmentFrequencies.entrySet())
out.printf("%d\t%d%n", alignmentFrequency.getKey(), alignmentFrequency.getValue());
super.onTraversalDone(result);
}
}