//-------------------------------------------------------------------------
public override IborCapletFloorletVolatilityCalibrationResult calibrate(IborCapletFloorletVolatilityDefinition definition, ZonedDateTime calibrationDateTime, RawOptionData capFloorData, RatesProvider ratesProvider)
{
ArgChecker.isTrue(ratesProvider.ValuationDate.Equals(calibrationDateTime.toLocalDate()), "valuationDate of ratesProvider should be coherent to calibrationDateTime");
ArgChecker.isTrue(definition is SabrIborCapletFloorletVolatilityCalibrationDefinition, "definition should be SabrIborCapletFloorletVolatilityCalibrationDefinition");
SabrIborCapletFloorletVolatilityCalibrationDefinition sabrDefinition = (SabrIborCapletFloorletVolatilityCalibrationDefinition)definition;
// unpack cap data, create node caps
IborIndex index = sabrDefinition.Index;
LocalDate calibrationDate = calibrationDateTime.toLocalDate();
LocalDate baseDate = index.EffectiveDateOffset.adjust(calibrationDate, ReferenceData);
LocalDate startDate = baseDate.plus(index.Tenor);
System.Func <Surface, IborCapletFloorletVolatilities> volatilitiesFunction = this.volatilitiesFunction(sabrDefinition, calibrationDateTime, capFloorData);
SurfaceMetadata metadata = sabrDefinition.createMetadata(capFloorData);
IList <Period> expiries = capFloorData.Expiries;
DoubleArray strikes = capFloorData.Strikes;
int nExpiries = expiries.Count;
IList <double> timeList = new List <double>();
IList <double> strikeList = new List <double>();
IList <double> volList = new List <double>();
IList <ResolvedIborCapFloorLeg> capList = new List <ResolvedIborCapFloorLeg>();
IList <double> priceList = new List <double>();
IList <double> errorList = new List <double>();
DoubleMatrix errorMatrix = capFloorData.Error.orElse(DoubleMatrix.filled(nExpiries, strikes.size(), 1d));
int[] startIndex = new int[nExpiries + 1];
for (int i = 0; i < nExpiries; ++i)
{
LocalDate endDate = baseDate.plus(expiries[i]);
DoubleArray volatilityForTime = capFloorData.Data.row(i);
DoubleArray errorForTime = errorMatrix.row(i);
reduceRawData(sabrDefinition, ratesProvider, capFloorData.Strikes, volatilityForTime, errorForTime, startDate, endDate, metadata, volatilitiesFunction, timeList, strikeList, volList, capList, priceList, errorList);
startIndex[i + 1] = volList.Count;
ArgChecker.isTrue(startIndex[i + 1] > startIndex[i], "no valid option data for {}", expiries[i]);
}
// create initial caplet vol surface
IList <CurveMetadata> metadataList = sabrDefinition.createSabrParameterMetadata();
DoubleArray initialValues = sabrDefinition.createFullInitialValues();
IList <Curve> curveList = sabrDefinition.createSabrParameterCurve(metadataList, initialValues);
SabrParameters sabrParamsInitial = SabrParameters.of(curveList[0], curveList[1], curveList[2], curveList[3], sabrDefinition.ShiftCurve, sabrDefinition.SabrVolatilityFormula);
SabrParametersIborCapletFloorletVolatilities vols = SabrParametersIborCapletFloorletVolatilities.of(sabrDefinition.Name, index, calibrationDateTime, sabrParamsInitial);
// solve least square
UncoupledParameterTransforms transform = new UncoupledParameterTransforms(initialValues, sabrDefinition.createFullTransform(TRANSFORMS), new BitArray());
System.Func <DoubleArray, DoubleArray> valueFunction = createPriceFunction(sabrDefinition, ratesProvider, vols, capList, priceList);
System.Func <DoubleArray, DoubleMatrix> jacobianFunction = createJacobianFunction(sabrDefinition, ratesProvider, vols, capList, priceList, index.Currency);
NonLinearTransformFunction transFunc = new NonLinearTransformFunction(valueFunction, jacobianFunction, transform);
LeastSquareResults res = solver.solve(DoubleArray.filled(priceList.Count, 1d), DoubleArray.copyOf(errorList), transFunc.FittingFunction, transFunc.FittingJacobian, transform.transform(initialValues));
LeastSquareResultsWithTransform resTransform = new LeastSquareResultsWithTransform(res, transform);
vols = updateParameters(sabrDefinition, vols, resTransform.ModelParameters);
return(IborCapletFloorletVolatilityCalibrationResult.ofLeastSquare(vols, res.ChiSq));
}
public virtual void testExactFitOddStart()
{
double[] start = new double[] { 0.01, 0.99, 0.9, 0.4 };
LeastSquareResultsWithTransform results = _fitter.solve(DoubleArray.copyOf(start));
double[] res = results.ModelParameters.toArray();
double eps = 1e-6;
assertEquals(ALPHA, res[0], eps);
assertEquals(BETA, res[1], eps);
assertEquals(RHO, res[2], eps);
assertEquals(NU, res[3], eps);
assertEquals(0.0, results.ChiSq, eps);
}
//JAVA TO C# CONVERTER TODO TASK: Most Java annotations will not have direct .NET equivalent attributes:
//ORIGINAL LINE: @SuppressWarnings("unused") public void testExactFit()
public virtual void testExactFit()
{
double[][] start = StartValues;
BitArray[] @fixed = FixedValues;
int nStartPoints = start.Length;
ArgChecker.isTrue(@fixed.Length == nStartPoints);
for (int trys = 0; trys < nStartPoints; trys++)
{
LeastSquareResultsWithTransform results = _fitter.solve(DoubleArray.copyOf(start[trys]), @fixed[trys]);
DoubleArray res = results.ModelParameters;
assertEquals(0.0, results.ChiSq, _chiSqEps);
int n = res.size();
T data = ModelData;
assertEquals(data.NumberOfParameters, n);
for (int i = 0; i < n; i++)
{
assertEquals(data.getParameter(i), res.get(i), _paramValueEps);
}
}
}
public virtual void testNoisyFitWithFixedBeta()
{
DoubleArray start = DoubleArray.of(0.1, 0.5, 0.0, 0.3);
BitArray @fixed = new BitArray();
@fixed.Set(1, true);
LeastSquareResultsWithTransform results = _nosiyFitter.solve(start, @fixed);
double[] res = results.ModelParameters.toArray();
double eps = 1e-2;
assertEquals(ALPHA, res[0], eps);
assertEquals(BETA, res[1], eps);
assertEquals(RHO, res[2], eps);
assertEquals(NU, res[3], eps);
assertEquals(0.0, results.ChiSq, 10.0d);
// sensitivity to data
DoubleMatrix sensitivity = results.ModelParameterSensitivityToData;
double shiftFd = 1.0E-5;
for (int i = 0; i < _cleanVols.Length; i++)
{
double[] volBumpedP = _noisyVols.Clone();
volBumpedP[i] += shiftFd;
SabrModelFitter fitterP = new SabrModelFitter(F, DoubleArray.copyOf(STRIKES), TIME_TO_EXPIRY, DoubleArray.copyOf(volBumpedP), DoubleArray.copyOf(_errors), Model);
LeastSquareResultsWithTransform resultsBumpedP = fitterP.solve(start, @fixed);
DoubleArray parameterBumpedP = resultsBumpedP.ModelParameters;
double[] volBumpedM = _noisyVols.Clone();
volBumpedM[i] -= shiftFd;
SabrModelFitter fitterM = new SabrModelFitter(F, DoubleArray.copyOf(STRIKES), TIME_TO_EXPIRY, DoubleArray.copyOf(volBumpedM), DoubleArray.copyOf(_errors), Model);
LeastSquareResultsWithTransform resultsBumpedM = fitterM.solve(start, @fixed);
DoubleArray parameterBumpedM = resultsBumpedM.ModelParameters;
DoubleArray sensitivityColumnFd = parameterBumpedP.minus(parameterBumpedM).dividedBy(2 * shiftFd);
assertTrue(sensitivityColumnFd.equalWithTolerance(sensitivity.column(i), 1.0E-2));
}
}
//-------------------------------------------------------------------------
public override IborCapletFloorletVolatilityCalibrationResult calibrate(IborCapletFloorletVolatilityDefinition definition, ZonedDateTime calibrationDateTime, RawOptionData capFloorData, RatesProvider ratesProvider)
{
ArgChecker.isTrue(ratesProvider.ValuationDate.Equals(calibrationDateTime.toLocalDate()), "valuationDate of ratesProvider should be coherent to calibrationDateTime");
ArgChecker.isTrue(definition is SabrIborCapletFloorletVolatilityBootstrapDefinition, "definition should be SabrIborCapletFloorletVolatilityBootstrapDefinition");
SabrIborCapletFloorletVolatilityBootstrapDefinition bsDefinition = (SabrIborCapletFloorletVolatilityBootstrapDefinition)definition;
IborIndex index = bsDefinition.Index;
LocalDate calibrationDate = calibrationDateTime.toLocalDate();
LocalDate baseDate = index.EffectiveDateOffset.adjust(calibrationDate, ReferenceData);
LocalDate startDate = baseDate.plus(index.Tenor);
System.Func <Surface, IborCapletFloorletVolatilities> volatilitiesFunction = this.volatilitiesFunction(bsDefinition, calibrationDateTime, capFloorData);
SurfaceMetadata metaData = bsDefinition.createMetadata(capFloorData);
IList <Period> expiries = capFloorData.Expiries;
int nExpiries = expiries.Count;
DoubleArray strikes = capFloorData.Strikes;
DoubleMatrix errorsMatrix = capFloorData.Error.orElse(DoubleMatrix.filled(nExpiries, strikes.size(), 1d));
IList <double> timeList = new List <double>();
IList <double> strikeList = new List <double>();
IList <double> volList = new List <double>();
IList <ResolvedIborCapFloorLeg> capList = new List <ResolvedIborCapFloorLeg>();
IList <double> priceList = new List <double>();
IList <double> errorList = new List <double>();
int[] startIndex = new int[nExpiries + 1];
for (int i = 0; i < nExpiries; ++i)
{
LocalDate endDate = baseDate.plus(expiries[i]);
DoubleArray volatilityData = capFloorData.Data.row(i);
DoubleArray errors = errorsMatrix.row(i);
reduceRawData(bsDefinition, ratesProvider, strikes, volatilityData, errors, startDate, endDate, metaData, volatilitiesFunction, timeList, strikeList, volList, capList, priceList, errorList);
startIndex[i + 1] = volList.Count;
ArgChecker.isTrue(startIndex[i + 1] > startIndex[i], "no valid option data for {}", expiries[i]);
}
IList <CurveMetadata> metadataList = bsDefinition.createSabrParameterMetadata();
DoubleArray timeToExpiries = DoubleArray.of(nExpiries, i => timeList[startIndex[i]]);
BitArray @fixed = new BitArray();
bool betaFix = false;
Curve betaCurve;
Curve rhoCurve;
if (bsDefinition.BetaCurve.Present)
{
betaFix = true;
@fixed.Set(1, true);
betaCurve = bsDefinition.BetaCurve.get();
rhoCurve = InterpolatedNodalCurve.of(metadataList[2], timeToExpiries, DoubleArray.filled(nExpiries), bsDefinition.Interpolator, bsDefinition.ExtrapolatorLeft, bsDefinition.ExtrapolatorRight);
}
else
{
@fixed.Set(2, true);
betaCurve = InterpolatedNodalCurve.of(metadataList[1], timeToExpiries, DoubleArray.filled(nExpiries), bsDefinition.Interpolator, bsDefinition.ExtrapolatorLeft, bsDefinition.ExtrapolatorRight);
rhoCurve = bsDefinition.RhoCurve.get();
}
InterpolatedNodalCurve alphaCurve = InterpolatedNodalCurve.of(metadataList[0], timeToExpiries, DoubleArray.filled(nExpiries), bsDefinition.Interpolator, bsDefinition.ExtrapolatorLeft, bsDefinition.ExtrapolatorRight);
InterpolatedNodalCurve nuCurve = InterpolatedNodalCurve.of(metadataList[3], timeToExpiries, DoubleArray.filled(nExpiries), bsDefinition.Interpolator, bsDefinition.ExtrapolatorLeft, bsDefinition.ExtrapolatorRight);
Curve shiftCurve = bsDefinition.ShiftCurve;
SabrParameters sabrParams = SabrParameters.of(alphaCurve, betaCurve, rhoCurve, nuCurve, shiftCurve, bsDefinition.SabrVolatilityFormula);
SabrParametersIborCapletFloorletVolatilities vols = SabrParametersIborCapletFloorletVolatilities.of(bsDefinition.Name, index, calibrationDateTime, sabrParams);
double totalChiSq = 0d;
ZonedDateTime prevExpiry = calibrationDateTime.minusDays(1L); // included if calibrationDateTime == fixingDateTime
for (int i = 0; i < nExpiries; ++i)
{
DoubleArray start = computeInitialValues(ratesProvider, betaCurve, shiftCurve, timeList, volList, capList, startIndex, i, betaFix, capFloorData.DataType);
UncoupledParameterTransforms transform = new UncoupledParameterTransforms(start, TRANSFORMS, @fixed);
int nCaplets = startIndex[i + 1] - startIndex[i];
int currentStart = startIndex[i];
System.Func <DoubleArray, DoubleArray> valueFunction = createPriceFunction(ratesProvider, vols, prevExpiry, capList, priceList, startIndex, nExpiries, i, nCaplets, betaFix);
System.Func <DoubleArray, DoubleMatrix> jacobianFunction = createJacobianFunction(ratesProvider, vols, prevExpiry, capList, priceList, index.Currency, startIndex, nExpiries, i, nCaplets, betaFix);
NonLinearTransformFunction transFunc = new NonLinearTransformFunction(valueFunction, jacobianFunction, transform);
DoubleArray adjustedPrices = this.adjustedPrices(ratesProvider, vols, prevExpiry, capList, priceList, startIndex, i, nCaplets);
DoubleArray errors = DoubleArray.of(nCaplets, n => errorList[currentStart + n]);
LeastSquareResults res = solver.solve(adjustedPrices, errors, transFunc.FittingFunction, transFunc.FittingJacobian, transform.transform(start));
LeastSquareResultsWithTransform resTransform = new LeastSquareResultsWithTransform(res, transform);
vols = updateParameters(vols, nExpiries, i, betaFix, resTransform.ModelParameters);
totalChiSq += res.ChiSq;
prevExpiry = capList[startIndex[i + 1] - 1].FinalFixingDateTime;
}
return(IborCapletFloorletVolatilityCalibrationResult.ofLeastSquare(vols, totalChiSq));
}
