// protected basic manipulation routines
private static List<Allele> makeAlleles(Collection<Allele> alleles) {
final List<Allele> alleleList = new ArrayList<Allele>(alleles.size());
boolean sawRef = false;
for (final Allele a : alleles) {
for (final Allele b : alleleList) {
if (a.equals(b, true))
throw new IllegalArgumentException("Duplicate allele added to VariantContext: " + a);
}
// deal with the case where the first allele isn't the reference
if (a.isReference()) {
if (sawRef)
throw new IllegalArgumentException(
"Alleles for a VariantContext must contain at most one reference allele: " + alleles);
alleleList.add(0, a);
sawRef = true;
} else alleleList.add(a);
}
if (alleleList.isEmpty())
throw new IllegalArgumentException(
"Cannot create a VariantContext with an empty allele list");
if (alleleList.get(0).isNonReference())
throw new IllegalArgumentException(
"Alleles for a VariantContext must contain at least one reference allele: " + alleles);
return alleleList;
}
/**
* Returns a context identical to this with the REF and ALT alleles reverse complemented.
*
* @param vc variant context
* @return new vc
*/
public static VariantContext reverseComplement(VariantContext vc) {
// create a mapping from original allele to reverse complemented allele
HashMap<Allele, Allele> alleleMap = new HashMap<Allele, Allele>(vc.getAlleles().size());
for (Allele originalAllele : vc.getAlleles()) {
Allele newAllele;
if (originalAllele.isNoCall() || originalAllele.isNull()) newAllele = originalAllele;
else
newAllele =
Allele.create(
BaseUtils.simpleReverseComplement(originalAllele.getBases()),
originalAllele.isReference());
alleleMap.put(originalAllele, newAllele);
}
// create new Genotype objects
GenotypesContext newGenotypes = GenotypesContext.create(vc.getNSamples());
for (final Genotype genotype : vc.getGenotypes()) {
List<Allele> newAlleles = new ArrayList<Allele>();
for (Allele allele : genotype.getAlleles()) {
Allele newAllele = alleleMap.get(allele);
if (newAllele == null) newAllele = Allele.NO_CALL;
newAlleles.add(newAllele);
}
newGenotypes.add(Genotype.modifyAlleles(genotype, newAlleles));
}
return new VariantContextBuilder(vc).alleles(alleleMap.values()).genotypes(newGenotypes).make();
}
protected void printVerboseData(
String pos,
VariantContext vc,
double PofF,
double phredScaledConfidence,
final GenotypeLikelihoodsCalculationModel.Model model) {
Allele refAllele = null, altAllele = null;
for (Allele allele : vc.getAlleles()) {
if (allele.isReference()) refAllele = allele;
else altAllele = allele;
}
for (int i = 0; i <= N; i++) {
StringBuilder AFline = new StringBuilder("AFINFO\t");
AFline.append(pos);
AFline.append("\t");
AFline.append(refAllele);
AFline.append("\t");
if (altAllele != null) AFline.append(altAllele);
else AFline.append("N/A");
AFline.append("\t");
AFline.append(i + "/" + N + "\t");
AFline.append(String.format("%.2f\t", ((float) i) / N));
AFline.append(String.format("%.8f\t", getAlleleFrequencyPriors(model)[i]));
verboseWriter.println(AFline.toString());
}
verboseWriter.println("P(f>0) = " + PofF);
verboseWriter.println("Qscore = " + phredScaledConfidence);
verboseWriter.println();
}
private void validateAlleles() {
// check alleles
boolean alreadySeenRef = false, alreadySeenNull = false;
for (Allele allele : alleles) {
// make sure there's only one reference allele
if (allele.isReference()) {
if (alreadySeenRef)
throw new IllegalArgumentException(
"BUG: Received two reference tagged alleles in VariantContext "
+ alleles
+ " this="
+ this);
alreadySeenRef = true;
}
if (allele.isNoCall()) {
throw new IllegalArgumentException(
"BUG: Cannot add a no call allele to a variant context " + alleles + " this=" + this);
}
// make sure there's only one null allele
if (allele.isNull()) {
if (alreadySeenNull)
throw new IllegalArgumentException(
"BUG: Received two null alleles in VariantContext " + alleles + " this=" + this);
alreadySeenNull = true;
}
}
// make sure there's one reference allele
if (!alreadySeenRef)
throw new IllegalArgumentException("No reference allele found in VariantContext");
// if ( getType() == Type.INDEL ) {
// if ( getReference().length() != (getLocation().size()-1) ) {
long length = (stop - start) + 1;
if ((getReference().isNull() && length != 1)
|| (getReference().isNonNull() && (length - getReference().length() > 1))) {
throw new IllegalStateException(
"BUG: GenomeLoc "
+ contig
+ ":"
+ start
+ "-"
+ stop
+ " has a size == "
+ length
+ " but the variation reference allele has length "
+ getReference().length()
+ " this = "
+ this);
}
}
/**
* helper routine for subcontext
*
* @param genotypes genotypes
* @return allele set
*/
private final Set<Allele> allelesOfGenotypes(Collection<Genotype> genotypes) {
final Set<Allele> alleles = new HashSet<Allele>();
boolean addedref = false;
for (final Genotype g : genotypes) {
for (final Allele a : g.getAlleles()) {
addedref = addedref || a.isReference();
if (a.isCalled()) alleles.add(a);
}
}
if (!addedref) alleles.add(getReference());
return alleles;
}
private static AlleleMapper resolveIncompatibleAlleles(
Allele refAllele, VariantContext vc, Set<Allele> allAlleles) {
if (refAllele.equals(vc.getReference())) return new AlleleMapper(vc);
else {
// we really need to do some work. The refAllele is the longest reference allele seen at this
// start site. So imagine it is:
//
// refAllele: ACGTGA
// myRef: ACGT
// myAlt: -
//
// We need to remap all of the alleles in vc to include the extra GA so that
// myRef => refAllele and myAlt => GA
//
Allele myRef = vc.getReference();
if (refAllele.length() <= myRef.length())
throw new ReviewedStingException(
"BUG: myRef=" + myRef + " is longer than refAllele=" + refAllele);
byte[] extraBases =
Arrays.copyOfRange(refAllele.getBases(), myRef.length(), refAllele.length());
// System.out.printf("Remapping allele at %s%n", vc);
// System.out.printf("ref %s%n", refAllele);
// System.out.printf("myref %s%n", myRef );
// System.out.printf("extrabases %s%n", new String(extraBases));
Map<Allele, Allele> map = new HashMap<Allele, Allele>();
for (Allele a : vc.getAlleles()) {
if (a.isReference()) map.put(a, refAllele);
else {
Allele extended = Allele.extend(a, extraBases);
for (Allele b : allAlleles) if (extended.equals(b)) extended = b;
// System.out.printf(" Extending %s => %s%n", a, extended);
map.put(a, extended);
}
}
// debugging
// System.out.printf("mapping %s%n", map);
return new AlleleMapper(map);
}
}
/**
* the actual constructor. Private access only
*
* @param source source
* @param contig the contig
* @param start the start base (one based)
* @param stop the stop reference base (one based)
* @param alleles alleles
* @param genotypes genotypes map
* @param log10PError qual
* @param filters filters: use null for unfiltered and empty set for passes filters
* @param attributes attributes
* @param referenceBaseForIndel padded reference base
* @param validationToPerform set of validation steps to take
*/
protected VariantContext(
String source,
String ID,
String contig,
long start,
long stop,
Collection<Allele> alleles,
GenotypesContext genotypes,
double log10PError,
Set<String> filters,
Map<String, Object> attributes,
Byte referenceBaseForIndel,
EnumSet<Validation> validationToPerform) {
if (contig == null) {
throw new IllegalArgumentException("Contig cannot be null");
}
this.contig = contig;
this.start = start;
this.stop = stop;
// intern for efficiency. equals calls will generate NPE if ID is inappropriately passed in as
// null
if (ID == null || ID.equals(""))
throw new IllegalArgumentException("ID field cannot be the null or the empty string");
this.ID = ID.equals(VCFConstants.EMPTY_ID_FIELD) ? VCFConstants.EMPTY_ID_FIELD : ID;
this.commonInfo = new CommonInfo(source, log10PError, filters, attributes);
REFERENCE_BASE_FOR_INDEL = referenceBaseForIndel;
// todo -- remove me when this check is no longer necessary
if (this.commonInfo.hasAttribute(ID_KEY))
throw new IllegalArgumentException(
"Trying to create a VariantContext with a ID key. Please use provided constructor argument ID");
if (alleles == null) {
throw new IllegalArgumentException("Alleles cannot be null");
}
// we need to make this a LinkedHashSet in case the user prefers a given ordering of alleles
this.alleles = makeAlleles(alleles);
if (genotypes == null || genotypes == NO_GENOTYPES) {
this.genotypes = NO_GENOTYPES;
} else {
this.genotypes = genotypes.immutable();
}
// cache the REF and ALT alleles
int nAlleles = alleles.size();
for (Allele a : alleles) {
if (a.isReference()) {
REF = a;
} else if (nAlleles == 2) { // only cache ALT when biallelic
ALT = a;
}
}
if (!validationToPerform.isEmpty()) {
validate(validationToPerform);
}
}
public static VariantContext createVariantContextWithTrimmedAlleles(VariantContext inputVC) {
// see if we need to trim common reference base from all alleles
boolean trimVC;
// We need to trim common reference base from all alleles in all genotypes if a ref base is
// common to all alleles
Allele refAllele = inputVC.getReference();
if (!inputVC.isVariant()) trimVC = false;
else if (refAllele.isNull()) trimVC = false;
else {
trimVC =
(AbstractVCFCodec.computeForwardClipping(
new ArrayList<Allele>(inputVC.getAlternateAlleles()),
inputVC.getReference().getDisplayString())
> 0);
}
// nothing to do if we don't need to trim bases
if (trimVC) {
List<Allele> alleles = new ArrayList<Allele>();
GenotypesContext genotypes = GenotypesContext.create();
// set the reference base for indels in the attributes
Map<String, Object> attributes = new TreeMap<String, Object>(inputVC.getAttributes());
Map<Allele, Allele> originalToTrimmedAlleleMap = new HashMap<Allele, Allele>();
for (Allele a : inputVC.getAlleles()) {
if (a.isSymbolic()) {
alleles.add(a);
originalToTrimmedAlleleMap.put(a, a);
} else {
// get bases for current allele and create a new one with trimmed bases
byte[] newBases = Arrays.copyOfRange(a.getBases(), 1, a.length());
Allele trimmedAllele = Allele.create(newBases, a.isReference());
alleles.add(trimmedAllele);
originalToTrimmedAlleleMap.put(a, trimmedAllele);
}
}
// detect case where we're trimming bases but resulting vc doesn't have any null allele. In
// that case, we keep original representation
// example: mixed records such as {TA*,TGA,TG}
boolean hasNullAlleles = false;
for (Allele a : originalToTrimmedAlleleMap.values()) {
if (a.isNull()) hasNullAlleles = true;
if (a.isReference()) refAllele = a;
}
if (!hasNullAlleles) return inputVC;
// now we can recreate new genotypes with trimmed alleles
for (final Genotype genotype : inputVC.getGenotypes()) {
List<Allele> originalAlleles = genotype.getAlleles();
List<Allele> trimmedAlleles = new ArrayList<Allele>();
for (Allele a : originalAlleles) {
if (a.isCalled()) trimmedAlleles.add(originalToTrimmedAlleleMap.get(a));
else trimmedAlleles.add(Allele.NO_CALL);
}
genotypes.add(Genotype.modifyAlleles(genotype, trimmedAlleles));
}
final VariantContextBuilder builder = new VariantContextBuilder(inputVC);
return builder
.alleles(alleles)
.genotypes(genotypes)
.attributes(attributes)
.referenceBaseForIndel(new Byte(inputVC.getReference().getBases()[0]))
.make();
}
return inputVC;
}
public static VariantContext createVariantContextWithPaddedAlleles(
VariantContext inputVC, boolean refBaseShouldBeAppliedToEndOfAlleles) {
// see if we need to pad common reference base from all alleles
boolean padVC;
// We need to pad a VC with a common base if the length of the reference allele is less than the
// length of the VariantContext.
// This happens because the position of e.g. an indel is always one before the actual event (as
// per VCF convention).
long locLength = (inputVC.getEnd() - inputVC.getStart()) + 1;
if (inputVC.hasSymbolicAlleles()) padVC = true;
else if (inputVC.getReference().length() == locLength) padVC = false;
else if (inputVC.getReference().length() == locLength - 1) padVC = true;
else
throw new IllegalArgumentException(
"Badly formed variant context at location "
+ String.valueOf(inputVC.getStart())
+ " in contig "
+ inputVC.getChr()
+ ". Reference length must be at most one base shorter than location size");
// nothing to do if we don't need to pad bases
if (padVC) {
if (!inputVC.hasReferenceBaseForIndel())
throw new ReviewedStingException(
"Badly formed variant context at location "
+ inputVC.getChr()
+ ":"
+ inputVC.getStart()
+ "; no padded reference base is available.");
Byte refByte = inputVC.getReferenceBaseForIndel();
List<Allele> alleles = new ArrayList<Allele>();
for (Allele a : inputVC.getAlleles()) {
// get bases for current allele and create a new one with trimmed bases
if (a.isSymbolic()) {
alleles.add(a);
} else {
String newBases;
if (refBaseShouldBeAppliedToEndOfAlleles)
newBases = a.getBaseString() + new String(new byte[] {refByte});
else newBases = new String(new byte[] {refByte}) + a.getBaseString();
alleles.add(Allele.create(newBases, a.isReference()));
}
}
// now we can recreate new genotypes with trimmed alleles
GenotypesContext genotypes = GenotypesContext.create(inputVC.getNSamples());
for (final Genotype g : inputVC.getGenotypes()) {
List<Allele> inAlleles = g.getAlleles();
List<Allele> newGenotypeAlleles = new ArrayList<Allele>(g.getAlleles().size());
for (Allele a : inAlleles) {
if (a.isCalled()) {
if (a.isSymbolic()) {
newGenotypeAlleles.add(a);
} else {
String newBases;
if (refBaseShouldBeAppliedToEndOfAlleles)
newBases = a.getBaseString() + new String(new byte[] {refByte});
else newBases = new String(new byte[] {refByte}) + a.getBaseString();
newGenotypeAlleles.add(Allele.create(newBases, a.isReference()));
}
} else {
// add no-call allele
newGenotypeAlleles.add(Allele.NO_CALL);
}
}
genotypes.add(
new Genotype(
g.getSampleName(),
newGenotypeAlleles,
g.getLog10PError(),
g.getFilters(),
g.getAttributes(),
g.isPhased()));
}
return new VariantContextBuilder(inputVC).alleles(alleles).genotypes(genotypes).make();
} else return inputVC;
}
/**
* Main entry function to calculate genotypes of a given VC with corresponding GL's
*
* @param tracker Tracker
* @param refContext Reference context
* @param rawContext Raw context
* @param stratifiedContexts Stratified alignment contexts
* @param vc Input VC
* @param model GL calculation model
* @param inheritAttributesFromInputVC Output VC will contain attributes inherited from input vc
* @return VC with assigned genotypes
*/
public VariantCallContext calculateGenotypes(
final RefMetaDataTracker tracker,
final ReferenceContext refContext,
final AlignmentContext rawContext,
Map<String, AlignmentContext> stratifiedContexts,
final VariantContext vc,
final GenotypeLikelihoodsCalculationModel.Model model,
final boolean inheritAttributesFromInputVC,
final Map<String, org.broadinstitute.sting.utils.genotyper.PerReadAlleleLikelihoodMap>
perReadAlleleLikelihoodMap) {
boolean limitedContext =
tracker == null || refContext == null || rawContext == null || stratifiedContexts == null;
// initialize the data for this thread if that hasn't been done yet
if (afcm.get() == null) {
afcm.set(AFCalcFactory.createAFCalc(UAC, N, logger));
}
// estimate our confidence in a reference call and return
if (vc.getNSamples() == 0) {
if (limitedContext) return null;
return (UAC.OutputMode != OUTPUT_MODE.EMIT_ALL_SITES
? estimateReferenceConfidence(vc, stratifiedContexts, getTheta(model), false, 1.0)
: generateEmptyContext(tracker, refContext, stratifiedContexts, rawContext));
}
AFCalcResult AFresult = afcm.get().getLog10PNonRef(vc, getAlleleFrequencyPriors(model));
// is the most likely frequency conformation AC=0 for all alternate alleles?
boolean bestGuessIsRef = true;
// determine which alternate alleles have AF>0
final List<Allele> myAlleles = new ArrayList<Allele>(vc.getAlleles().size());
final List<Integer> alleleCountsofMLE = new ArrayList<Integer>(vc.getAlleles().size());
myAlleles.add(vc.getReference());
for (int i = 0; i < AFresult.getAllelesUsedInGenotyping().size(); i++) {
final Allele alternateAllele = AFresult.getAllelesUsedInGenotyping().get(i);
if (alternateAllele.isReference()) continue;
// we are non-ref if the probability of being non-ref > the emit confidence.
// the emit confidence is phred-scaled, say 30 => 10^-3.
// the posterior AF > 0 is log10: -5 => 10^-5
// we are non-ref if 10^-5 < 10^-3 => -5 < -3
final boolean isNonRef =
AFresult.isPolymorphic(alternateAllele, UAC.STANDARD_CONFIDENCE_FOR_EMITTING / -10.0);
// if the most likely AC is not 0, then this is a good alternate allele to use
if (isNonRef) {
myAlleles.add(alternateAllele);
alleleCountsofMLE.add(AFresult.getAlleleCountAtMLE(alternateAllele));
bestGuessIsRef = false;
}
// if in GENOTYPE_GIVEN_ALLELES mode, we still want to allow the use of a poor allele
else if (UAC.GenotypingMode
== GenotypeLikelihoodsCalculationModel.GENOTYPING_MODE.GENOTYPE_GIVEN_ALLELES) {
myAlleles.add(alternateAllele);
alleleCountsofMLE.add(AFresult.getAlleleCountAtMLE(alternateAllele));
}
}
final double PoFGT0 = Math.pow(10, AFresult.getLog10PosteriorOfAFGT0());
// note the math.abs is necessary because -10 * 0.0 => -0.0 which isn't nice
final double phredScaledConfidence =
Math.abs(
!bestGuessIsRef
|| UAC.GenotypingMode
== GenotypeLikelihoodsCalculationModel.GENOTYPING_MODE
.GENOTYPE_GIVEN_ALLELES
? -10 * AFresult.getLog10PosteriorOfAFEq0()
: -10 * AFresult.getLog10PosteriorOfAFGT0());
// return a null call if we don't pass the confidence cutoff or the most likely allele frequency
// is zero
if (UAC.OutputMode != OUTPUT_MODE.EMIT_ALL_SITES
&& !passesEmitThreshold(phredScaledConfidence, bestGuessIsRef)) {
// technically, at this point our confidence in a reference call isn't accurately estimated
// because it didn't take into account samples with no data, so let's get a better estimate
return limitedContext
? null
: estimateReferenceConfidence(vc, stratifiedContexts, getTheta(model), true, PoFGT0);
}
// start constructing the resulting VC
final GenomeLoc loc = genomeLocParser.createGenomeLoc(vc);
final VariantContextBuilder builder =
new VariantContextBuilder(
"UG_call", loc.getContig(), loc.getStart(), loc.getStop(), myAlleles);
builder.log10PError(phredScaledConfidence / -10.0);
if (!passesCallThreshold(phredScaledConfidence)) builder.filters(filter);
// create the genotypes
final GenotypesContext genotypes = afcm.get().subsetAlleles(vc, myAlleles, true, ploidy);
builder.genotypes(genotypes);
// print out stats if we have a writer
if (verboseWriter != null && !limitedContext)
printVerboseData(refContext.getLocus().toString(), vc, PoFGT0, phredScaledConfidence, model);
// *** note that calculating strand bias involves overwriting data structures, so we do that
// last
final HashMap<String, Object> attributes = new HashMap<String, Object>();
// inherit attributed from input vc if requested
if (inheritAttributesFromInputVC) attributes.putAll(vc.getAttributes());
// if the site was downsampled, record that fact
if (!limitedContext && rawContext.hasPileupBeenDownsampled())
attributes.put(VCFConstants.DOWNSAMPLED_KEY, true);
if (UAC.ANNOTATE_NUMBER_OF_ALLELES_DISCOVERED)
attributes.put(NUMBER_OF_DISCOVERED_ALLELES_KEY, vc.getAlternateAlleles().size());
// add the MLE AC and AF annotations
if (alleleCountsofMLE.size() > 0) {
attributes.put(VCFConstants.MLE_ALLELE_COUNT_KEY, alleleCountsofMLE);
final int AN = builder.make().getCalledChrCount();
final ArrayList<Double> MLEfrequencies = new ArrayList<Double>(alleleCountsofMLE.size());
// the MLEAC is allowed to be larger than the AN (e.g. in the case of all PLs being 0, the GT
// is ./. but the exact model may arbitrarily choose an AC>1)
for (int AC : alleleCountsofMLE) MLEfrequencies.add(Math.min(1.0, (double) AC / (double) AN));
attributes.put(VCFConstants.MLE_ALLELE_FREQUENCY_KEY, MLEfrequencies);
}
if (UAC.COMPUTE_SLOD && !limitedContext && !bestGuessIsRef) {
// final boolean DEBUG_SLOD = false;
// the overall lod
// double overallLog10PofNull = AFresult.log10AlleleFrequencyPosteriors[0];
double overallLog10PofF = AFresult.getLog10LikelihoodOfAFGT0();
// if ( DEBUG_SLOD ) System.out.println("overallLog10PofF=" + overallLog10PofF);
List<Allele> allAllelesToUse = builder.make().getAlleles();
// the forward lod
VariantContext vcForward =
calculateLikelihoods(
tracker,
refContext,
stratifiedContexts,
AlignmentContextUtils.ReadOrientation.FORWARD,
allAllelesToUse,
false,
model,
perReadAlleleLikelihoodMap);
AFresult = afcm.get().getLog10PNonRef(vcForward, getAlleleFrequencyPriors(model));
// double[] normalizedLog10Posteriors =
// MathUtils.normalizeFromLog10(AFresult.log10AlleleFrequencyPosteriors, true);
double forwardLog10PofNull = AFresult.getLog10LikelihoodOfAFEq0();
double forwardLog10PofF = AFresult.getLog10LikelihoodOfAFGT0();
// if ( DEBUG_SLOD ) System.out.println("forwardLog10PofNull=" + forwardLog10PofNull + ",
// forwardLog10PofF=" + forwardLog10PofF);
// the reverse lod
VariantContext vcReverse =
calculateLikelihoods(
tracker,
refContext,
stratifiedContexts,
AlignmentContextUtils.ReadOrientation.REVERSE,
allAllelesToUse,
false,
model,
perReadAlleleLikelihoodMap);
AFresult = afcm.get().getLog10PNonRef(vcReverse, getAlleleFrequencyPriors(model));
// normalizedLog10Posteriors =
// MathUtils.normalizeFromLog10(AFresult.log10AlleleFrequencyPosteriors, true);
double reverseLog10PofNull = AFresult.getLog10LikelihoodOfAFEq0();
double reverseLog10PofF = AFresult.getLog10LikelihoodOfAFGT0();
// if ( DEBUG_SLOD ) System.out.println("reverseLog10PofNull=" + reverseLog10PofNull + ",
// reverseLog10PofF=" + reverseLog10PofF);
double forwardLod = forwardLog10PofF + reverseLog10PofNull - overallLog10PofF;
double reverseLod = reverseLog10PofF + forwardLog10PofNull - overallLog10PofF;
// if ( DEBUG_SLOD ) System.out.println("forward lod=" + forwardLod + ", reverse lod=" +
// reverseLod);
// strand score is max bias between forward and reverse strands
double strandScore = Math.max(forwardLod, reverseLod);
// rescale by a factor of 10
strandScore *= 10.0;
// logger.debug(String.format("SLOD=%f", strandScore));
if (!Double.isNaN(strandScore)) attributes.put("SB", strandScore);
}
// finish constructing the resulting VC
builder.attributes(attributes);
VariantContext vcCall = builder.make();
// if we are subsetting alleles (either because there were too many or because some were not
// polymorphic)
// then we may need to trim the alleles (because the original VariantContext may have had to pad
// at the end).
if (myAlleles.size() != vc.getAlleles().size()
&& !limitedContext) // limitedContext callers need to handle allele trimming on their own to
// keep their perReadAlleleLikelihoodMap alleles in sync
vcCall = VariantContextUtils.reverseTrimAlleles(vcCall);
if (annotationEngine != null
&& !limitedContext) { // limitedContext callers need to handle annotations on their own by
// calling their own annotationEngine
// Note: we want to use the *unfiltered* and *unBAQed* context for the annotations
final ReadBackedPileup pileup = rawContext.getBasePileup();
stratifiedContexts = AlignmentContextUtils.splitContextBySampleName(pileup);
vcCall =
annotationEngine.annotateContext(
tracker, refContext, stratifiedContexts, vcCall, perReadAlleleLikelihoodMap);
}
return new VariantCallContext(vcCall, confidentlyCalled(phredScaledConfidence, PoFGT0));
}