Examples with SamLocusIterator htsjdk.samtools.util.SamLocusIterator used on opensource projects

Example 1 with SamLocusIterator

use of htsjdk.samtools.util.SamLocusIterator in project gatk by broadinstitute.

the class HetPulldownCalculatorUnitTest method inputGetPileupBaseCount.

@DataProvider(name = "inputGetPileupBaseCount")
public Object[][] inputGetPileupBaseCount() throws IOException {
    try (final SamReader bamReader = SamReaderFactory.makeDefault().open(NORMAL_BAM_FILE)) {
        final IntervalList intervals = new IntervalList(bamReader.getFileHeader());
        intervals.add(new Interval("1", 100, 100));
        intervals.add(new Interval("1", 11000, 11000));
        intervals.add(new Interval("1", 14000, 14000));
        intervals.add(new Interval("1", 14630, 14630));
        final SamLocusIterator locusIterator = new SamLocusIterator(bamReader, intervals);
        final Nucleotide.Counter baseCounts1 = makeBaseCounts(0, 0, 0, 0);
        final Nucleotide.Counter baseCounts2 = makeBaseCounts(0, 9, 0, 0);
        final Nucleotide.Counter baseCounts3 = makeBaseCounts(12, 0, 0, 0);
        final Nucleotide.Counter baseCounts4 = makeBaseCounts(0, 0, 8, 9);
        if (!locusIterator.hasNext()) {
            throw new SAMException("Can't get locus to start iteration. Check that " + NORMAL_BAM_FILE.toString() + " contains 1:0-16000.");
        }
        final SamLocusIterator.LocusInfo locus1 = locusIterator.next();
        final SamLocusIterator.LocusInfo locus2 = locusIterator.next();
        final SamLocusIterator.LocusInfo locus3 = locusIterator.next();
        final SamLocusIterator.LocusInfo locus4 = locusIterator.next();
        locusIterator.close();
        return new Object[][] { { locus1, baseCounts1 }, { locus2, baseCounts2 }, { locus3, baseCounts3 }, { locus4, baseCounts4 } };
    }
}

Example 2 with SamLocusIterator

use of htsjdk.samtools.util.SamLocusIterator in project gatk-protected by broadinstitute.

the class BayesianHetPulldownCalculator method getSamLocusIteratorWithDefaultFilters.

/**
     * Returns a {@link SamLocusIterator} object for a given {@link SamReader} and {@link IntervalList} with filters
     * on minimum base quality and minimum mapping quality
     *
     * @param samReader a SamReader object
     * @return a SamLocusIterator object
     */
private SamLocusIterator getSamLocusIteratorWithDefaultFilters(final SamReader samReader) {
    final SamLocusIterator locusIterator = new SamLocusIterator(samReader, snpIntervals, false);
    /* set read and locus filters */
    final List<SamRecordFilter> samFilters = Arrays.asList(new NotPrimaryAlignmentFilter(), new DuplicateReadFilter());
    locusIterator.setSamFilters(samFilters);
    locusIterator.setEmitUncoveredLoci(false);
    locusIterator.setIncludeNonPfReads(false);
    locusIterator.setMappingQualityScoreCutoff(minMappingQuality);
    locusIterator.setQualityScoreCutoff(minBaseQuality);
    return locusIterator;
}

Example 3 with SamLocusIterator

use of htsjdk.samtools.util.SamLocusIterator in project gatk-protected by broadinstitute.

the class BayesianHetPulldownCalculator method getHetPulldown.

/**
     * For a given normal or tumor BAM file, walks through the list of common SNPs,
     * {@link BayesianHetPulldownCalculator#snpIntervals}), detects heterozygous sites, and returns
     * a {@link Pulldown} containing detailed information on the called heterozygous SNP sites.
     *
     * The {@code hetCallingStrigency} parameters sets the threshold posterior for calling a Het SNP site:
     *
     *      hetPosteriorThreshold = 1 - 10^{-hetCallingStringency}
     *      hetThresholdLogOdds = log(hetPosteriorThreshold/(1-hetPosteriorThreshold))
     *                          = log(10^{hetCallingStringency} - 1)
     *
     * (see CNV-methods.pdf for details)
     *
     * @param bamFile sorted BAM file for sample
     * @param hetCallingStringency strigency for calling a Het site
     * @return Pulldown of heterozygous SNP sites in 1-based format
     */
public Pulldown getHetPulldown(final File bamFile, final double hetCallingStringency) {
    /* log odds from stringency */
    final double hetThresholdLogOdds = FastMath.log(FastMath.pow(10, hetCallingStringency) - 1);
    try (final SamReader bamReader = SamReaderFactory.makeDefault().validationStringency(validationStringency).referenceSequence(refFile).open(bamFile);
        final ReferenceSequenceFileWalker refWalker = new ReferenceSequenceFileWalker(refFile)) {
        if (bamReader.getFileHeader().getSortOrder() != SAMFileHeader.SortOrder.coordinate) {
            throw new UserException.BadInput("BAM file " + bamFile.toString() + " must be coordinate sorted.");
        }
        final Pulldown hetPulldown = new Pulldown(bamReader.getFileHeader());
        final SamLocusIterator locusIterator = getSamLocusIteratorWithDefaultFilters(bamReader);
        final int totalNumberOfSNPs = snpIntervals.size();
        logger.info("Examining " + totalNumberOfSNPs + " sites in total...");
        int locusCount = 0;
        for (final SamLocusIterator.LocusInfo locus : locusIterator) {
            if (locusCount % NUMBER_OF_SITES_PER_LOGGED_STATUS_UPDATE == 0) {
                logger.info("Examined " + locusCount + " covered sites.");
            }
            locusCount++;
            final int totalReadCount = locus.getRecordAndOffsets().size();
            if (totalReadCount <= readDepthThreshold) {
                continue;
            }
            final Nucleotide refBase = Nucleotide.valueOf(refWalker.get(locus.getSequenceIndex()).getBases()[locus.getPosition() - 1]);
            if (!isProperBase(refBase)) {
                logger.warn(String.format("The reference position at %d has an unknown base call (value: %s). Even though" + " this position is indicated to be a possible heterozygous SNP in the provided SNP interval list," + " no inference can be made. Continuing ...", locus.getPosition(), refBase.toString()));
                continue;
            }
            final Map<Nucleotide, List<BaseQuality>> baseQualities = getPileupBaseQualities(locus);
            final Nucleotide altBase = inferAltFromPileup(baseQualities, refBase);
            /* calculate Het log odds */
            final double hetLogLikelihood = getHetLogLikelihood(baseQualities, refBase, altBase);
            final double homLogLikelihood = getHomLogLikelihood(baseQualities, refBase, altBase, DEFAULT_PRIOR_REF_HOM);
            final double hetLogOdds = (hetLogLikelihood + FastMath.log(DEFAULT_PRIOR_HET)) - (homLogLikelihood + FastMath.log(1 - DEFAULT_PRIOR_HET));
            if (hetLogOdds > hetThresholdLogOdds) {
                hetPulldown.add(new AllelicCount(new SimpleInterval(locus.getSequenceName(), locus.getPosition(), locus.getPosition()), baseQualities.get(refBase).size(), baseQualities.get(altBase).size(), refBase, altBase, totalReadCount, hetLogOdds));
            }
        }
        logger.info(locusCount + " covered sites out of " + totalNumberOfSNPs + " total sites were examined.");
        return hetPulldown;
    } catch (final IOException | SAMFormatException e) {
        throw new UserException(e.getMessage());
    }
}

Example 4 with SamLocusIterator

use of htsjdk.samtools.util.SamLocusIterator in project gatk-protected by broadinstitute.

the class HetPulldownCalculator method getHetPulldown.

/**
     * For a normal or tumor sample, returns a data structure giving (intervals, reference counts, alternate counts),
     * where intervals give positions of likely heterozygous SNP sites.
     *
     * <p>
     *     For a normal sample:
     *     <ul>
     *         The IntervalList snpIntervals gives common SNP sites in 1-based format.
     *     </ul>
     *     <ul>
     *         The p-value threshold must be specified for a two-sided binomial test,
     *         which is used to determine SNP sites from snpIntervals that are
     *         compatible with a heterozygous SNP, given the sample.  Only these sites are output.
     *     </ul>
     * </p>
     * <p>
     *     For a tumor sample:
     *     <ul>
     *         The IntervalList snpIntervals gives heterozygous SNP sites likely to be present in the normal sample.
     *         This should be from {@link HetPulldownCalculator#getNormal} in 1-based format.
     *         Only these sites are output.
     *     </ul>
     * </p>
     * @param bamFile           sorted BAM file for sample
     * @param snpIntervals      IntervalList of SNP sites
     * @param sampleType        flag indicating type of sample (SampleType.NORMAL or SampleType.TUMOR)
     *                          (determines whether to perform binomial test)
     * @param pvalThreshold     p-value threshold for two-sided binomial test, used for normal sample
     * @param minimumRawReads   minimum number of total reads that must be present at a het site
     * @return                  Pulldown of heterozygous SNP sites in 1-based format
     */
private Pulldown getHetPulldown(final File bamFile, final IntervalList snpIntervals, final SampleType sampleType, final double pvalThreshold, final int minimumRawReads) {
    try (final SamReader bamReader = SamReaderFactory.makeDefault().validationStringency(validationStringency).referenceSequence(refFile).open(bamFile);
        final ReferenceSequenceFileWalker refWalker = new ReferenceSequenceFileWalker(refFile)) {
        if (bamReader.getFileHeader().getSortOrder() != SAMFileHeader.SortOrder.coordinate) {
            throw new UserException.BadInput("BAM file " + bamFile.toString() + " must be coordinate sorted.");
        }
        final Pulldown hetPulldown = new Pulldown(bamReader.getFileHeader());
        final int totalNumberOfSNPs = snpIntervals.size();
        final SamLocusIterator locusIterator = new SamLocusIterator(bamReader, snpIntervals, totalNumberOfSNPs < MAX_INTERVALS_FOR_INDEX);
        //set read and locus filters [note: read counts match IGV, but off by a few from pysam.mpileup]
        final List<SamRecordFilter> samFilters = Arrays.asList(new NotPrimaryAlignmentFilter(), new DuplicateReadFilter());
        locusIterator.setSamFilters(samFilters);
        locusIterator.setEmitUncoveredLoci(false);
        locusIterator.setIncludeNonPfReads(false);
        locusIterator.setMappingQualityScoreCutoff(minMappingQuality);
        locusIterator.setQualityScoreCutoff(minBaseQuality);
        logger.info("Examining " + totalNumberOfSNPs + " sites in total...");
        int locusCount = 0;
        for (final SamLocusIterator.LocusInfo locus : locusIterator) {
            if (locusCount % NUMBER_OF_SITES_PER_LOGGED_STATUS_UPDATE == 0) {
                logger.info("Examined " + locusCount + " covered sites.");
            }
            locusCount++;
            //include N, etc. reads here
            final int totalReadCount = locus.getRecordAndOffsets().size();
            if (totalReadCount < minimumRawReads) {
                continue;
            }
            final Nucleotide.Counter baseCounts = getPileupBaseCounts(locus);
            //only include total ACGT counts in binomial test (exclude N, etc.)
            final int totalBaseCount = Arrays.stream(BASES).mapToInt(b -> (int) baseCounts.get(b)).sum();
            if (sampleType == SampleType.NORMAL && !isPileupHetCompatible(baseCounts, totalBaseCount, pvalThreshold)) {
                continue;
            }
            final Nucleotide refBase = Nucleotide.valueOf(refWalker.get(locus.getSequenceIndex()).getBases()[locus.getPosition() - 1]);
            final int refReadCount = (int) baseCounts.get(refBase);
            final int altReadCount = totalBaseCount - refReadCount;
            hetPulldown.add(new AllelicCount(new SimpleInterval(locus.getSequenceName(), locus.getPosition(), locus.getPosition()), refReadCount, altReadCount));
        }
        logger.info(locusCount + " covered sites out of " + totalNumberOfSNPs + " total sites were examined.");
        return hetPulldown;
    } catch (final IOException | SAMFormatException e) {
        throw new UserException(e.getMessage());
    }
}

Example 5 with SamLocusIterator

use of htsjdk.samtools.util.SamLocusIterator in project gatk by broadinstitute.

the class AllelicCountCollector method collect.

/**
     * Returns an {@link AllelicCountCollection} based on the pileup at sites (specified by an interval list)
     * in a sorted BAM file.  Reads and bases below the specified mapping quality and base quality, respectively,
     * are filtered out of the pileup.  The alt count is defined as the total count minus the ref count, and the
     * alt nucleotide is defined as the non-ref base with the highest count, with ties broken by the order of the
     * bases in {@link AllelicCountCollector#BASES}.
     * @param bamFile           sorted BAM file
     * @param siteIntervals     interval list of sites
     * @param minMappingQuality minimum mapping quality required for reads to be included in pileup
     * @param minBaseQuality    minimum base quality required for bases to be included in pileup
     * @return                  AllelicCountCollection of ref/alt counts at sites in BAM file
     */
public AllelicCountCollection collect(final File bamFile, final IntervalList siteIntervals, final int minMappingQuality, final int minBaseQuality) {
    try (final SamReader reader = readerFactory.open(bamFile)) {
        ParamUtils.isPositiveOrZero(minMappingQuality, "Minimum mapping quality must be nonnegative.");
        ParamUtils.isPositiveOrZero(minBaseQuality, "Minimum base quality must be nonnegative.");
        if (reader.getFileHeader().getSortOrder() != SAMFileHeader.SortOrder.coordinate) {
            throw new UserException.BadInput("BAM file " + bamFile.toString() + " must be coordinate sorted.");
        }
        final int numberOfSites = siteIntervals.size();
        final boolean useIndex = numberOfSites < MAX_INTERVALS_FOR_INDEX;
        final SamLocusIterator locusIterator = new SamLocusIterator(reader, siteIntervals, useIndex);
        //set read and locus filters [note: read counts match IGV, but off by a few from pysam.mpileup]
        final List<SamRecordFilter> samFilters = Arrays.asList(new NotPrimaryAlignmentFilter(), new DuplicateReadFilter());
        locusIterator.setSamFilters(samFilters);
        locusIterator.setEmitUncoveredLoci(true);
        locusIterator.setIncludeNonPfReads(false);
        locusIterator.setMappingQualityScoreCutoff(minMappingQuality);
        locusIterator.setQualityScoreCutoff(minBaseQuality);
        logger.info("Examining " + numberOfSites + " sites in total...");
        int locusCount = 0;
        final AllelicCountCollection counts = new AllelicCountCollection();
        for (final SamLocusIterator.LocusInfo locus : locusIterator) {
            if (locusCount % NUMBER_OF_SITES_PER_LOGGED_STATUS_UPDATE == 0) {
                logger.info("Examined " + locusCount + " sites.");
            }
            locusCount++;
            final Nucleotide refBase = Nucleotide.valueOf(referenceWalker.get(locus.getSequenceIndex()).getBases()[locus.getPosition() - 1]);
            if (!BASES.contains(refBase)) {
                logger.warn(String.format("The reference position at %d has an unknown base call (value: %s). Skipping...", locus.getPosition(), refBase.toString()));
                continue;
            }
            final Nucleotide.Counter baseCounts = getPileupBaseCounts(locus);
            //only include total ACGT counts in binomial test (exclude N, etc.)
            final int totalBaseCount = BASES.stream().mapToInt(b -> (int) baseCounts.get(b)).sum();
            final int refReadCount = (int) baseCounts.get(refBase);
            //we take alt = total - ref instead of the actual alt count
            final int altReadCount = totalBaseCount - refReadCount;
            final Nucleotide altBase = inferAltFromPileupBaseCounts(baseCounts, refBase);
            counts.add(new AllelicCount(new SimpleInterval(locus.getSequenceName(), locus.getPosition(), locus.getPosition()), refReadCount, altReadCount, refBase, altBase));
        }
        logger.info(locusCount + " sites out of " + numberOfSites + " total sites were examined.");
        return counts;
    } catch (final IOException | SAMFormatException e) {
        throw new UserException("Unable to collect allelic counts from " + bamFile);
    }
}