private CurrencyParameterSensitivities sensitivityCreidtCurve <T>(ImmutableCreditRatesProvider provider, System.Func <ImmutableCreditRatesProvider, CurrencyAmount> valueFn, MetaProperty <ImmutableMap <T, LegalEntitySurvivalProbabilities> > metaProperty, CurrencyAmount valueInit)
{
ImmutableMap <T, LegalEntitySurvivalProbabilities> baseCurves = metaProperty.get(provider);
CurrencyParameterSensitivities result = CurrencyParameterSensitivities.empty();
foreach (T key in baseCurves.Keys)
{
LegalEntitySurvivalProbabilities credit = baseCurves.get(key);
CreditDiscountFactors creditDiscountFactors = credit.SurvivalProbabilities;
DiscountFactors discountFactors = creditDiscountFactors.toDiscountFactors();
Curve curve = checkDiscountFactors(discountFactors);
int paramCount = curve.ParameterCount;
double[] sensitivity = new double[paramCount];
for (int i = 0; i < paramCount; i++)
{
Curve dscBumped = curve.withParameter(i, curve.getParameter(i) + shift);
IDictionary <T, LegalEntitySurvivalProbabilities> mapBumped = new Dictionary <T, LegalEntitySurvivalProbabilities>(baseCurves);
mapBumped[key] = LegalEntitySurvivalProbabilities.of(credit.LegalEntityId, createCreditDiscountFactors(creditDiscountFactors, dscBumped));
ImmutableCreditRatesProvider providerDscBumped = provider.toBuilder().set(metaProperty, mapBumped).build();
sensitivity[i] = (valueFn(providerDscBumped).Amount - valueInit.Amount) / shift;
}
result = result.combinedWith(curve.createParameterSensitivity(valueInit.Currency, DoubleArray.copyOf(sensitivity)));
}
return(result);
}
private LegalEntitySurvivalProbabilities(StandardId legalEntityId, CreditDiscountFactors survivalProbabilities)
{
JodaBeanUtils.notNull(legalEntityId, "legalEntityId");
JodaBeanUtils.notNull(survivalProbabilities, "survivalProbabilities");
this.legalEntityId = legalEntityId;
this.survivalProbabilities = survivalProbabilities;
}
//-------------------------------------------------------------------------
private static CreditRatesProvider createCreditRatesProviderSingle(LocalDate valuationDate, bool isSingle)
{
IsdaCreditDiscountFactors yc = IsdaCreditDiscountFactors.of(USD, valuationDate, NODAL_YC);
CreditDiscountFactors cc = isSingle ? IsdaCreditDiscountFactors.of(USD, valuationDate, NODAL_CC_SINGLE) : IsdaCreditDiscountFactors.of(USD, valuationDate, NODAL_CC);
ConstantRecoveryRates rr = ConstantRecoveryRates.of(INDEX_ID, valuationDate, RECOVERY_RATE);
return(ImmutableCreditRatesProvider.builder().valuationDate(valuationDate).creditCurves(ImmutableMap.of(Pair.of(INDEX_ID, USD), LegalEntitySurvivalProbabilities.of(INDEX_ID, cc))).discountCurves(ImmutableMap.of(USD, yc)).recoveryRateCurves(ImmutableMap.of(INDEX_ID, rr)).build());
}
// return correct instance of CreditDiscountFactors
private CreditDiscountFactors createCreditDiscountFactors(CreditDiscountFactors originalDsc, Curve bumpedCurve)
{
if (originalDsc is IsdaCreditDiscountFactors && bumpedCurve is NodalCurve)
{
IsdaCreditDiscountFactors isdaDsc = (IsdaCreditDiscountFactors)originalDsc;
return(isdaDsc.withCurve((NodalCurve)bumpedCurve));
}
throw new System.ArgumentException("Not supported");
}
public CreditDiscountFactors discountFactors(Currency currency)
{
CreditDiscountFactors discountFactors = discountCurves.get(currency);
if (discountFactors == null)
{
throw new System.ArgumentException("Unable to find discount curve: " + currency);
}
return(discountFactors);
}
public CreditDiscountFactors discountFactors(Currency currency)
{
CurveId curveId = lookup.DiscountCurveIds.get(currency);
if (curveId == null)
{
throw new MarketDataNotFoundException("Unable to find discount curve: " + currency);
}
Curve curve = marketData.getValue(curveId);
return(CreditDiscountFactors.of(currency, ValuationDate, curve));
}
private Pair <CreditDiscountFactors, LegalEntitySurvivalProbabilities> reduceDiscountFactors(ResolvedCds cds, CreditRatesProvider ratesProvider)
{
Currency currency = cds.Currency;
CreditDiscountFactors discountFactors = ratesProvider.discountFactors(currency);
ArgChecker.isTrue(discountFactors.IsdaCompliant, "discount factors must be IsdaCompliantZeroRateDiscountFactors");
LegalEntitySurvivalProbabilities survivalProbabilities = ratesProvider.survivalProbabilities(cds.LegalEntityId, currency);
ArgChecker.isTrue(survivalProbabilities.SurvivalProbabilities.IsdaCompliant, "survival probabilities must be IsdaCompliantZeroRateDiscountFactors");
ArgChecker.isTrue(discountFactors.DayCount.Equals(survivalProbabilities.SurvivalProbabilities.DayCount), "day count conventions of discounting curve and credit curve must be the same");
return(Pair.of(discountFactors, survivalProbabilities));
}
//-------------------------------------------------------------------------
public LegalEntitySurvivalProbabilities survivalProbabilities(StandardId legalEntityId, Currency currency)
{
CurveId curveId = lookup.CreditCurveIds.get(Pair.of(legalEntityId, currency));
if (curveId == null)
{
throw new MarketDataNotFoundException("Unable to find credit curve: " + legalEntityId + ", " + currency);
}
Curve curve = marketData.getValue(curveId);
CreditDiscountFactors survivalProbabilities = CreditDiscountFactors.of(currency, ValuationDate, curve);
return(LegalEntitySurvivalProbabilities.of(legalEntityId, survivalProbabilities));
}
internal virtual Triple <CreditDiscountFactors, LegalEntitySurvivalProbabilities, double> reduceDiscountFactors(ResolvedCds cds, CreditRatesProvider ratesProvider)
{
Currency currency = cds.Currency;
CreditDiscountFactors discountFactors = ratesProvider.discountFactors(currency);
ArgChecker.isTrue(discountFactors.IsdaCompliant, "discount factors must be IsdaCompliantZeroRateDiscountFactors");
LegalEntitySurvivalProbabilities survivalProbabilities = ratesProvider.survivalProbabilities(cds.LegalEntityId, currency);
ArgChecker.isTrue(survivalProbabilities.SurvivalProbabilities.IsdaCompliant, "survival probabilities must be IsdaCompliantZeroRateDiscountFactors");
ArgChecker.isTrue(discountFactors.DayCount.Equals(survivalProbabilities.SurvivalProbabilities.DayCount), "day count conventions of discounting curve and credit curve must be the same");
double indexFactor = ((IsdaCreditDiscountFactors)survivalProbabilities.SurvivalProbabilities).Curve.Metadata.getInfo(CurveInfoType.CDS_INDEX_FACTOR);
return(Triple.of(discountFactors, survivalProbabilities, indexFactor));
}
public override Builder set(string propertyName, object newValue)
{
switch (propertyName.GetHashCode())
{
case 866287159: // legalEntityId
this.legalEntityId = (StandardId)newValue;
break;
case -2020275979: // survivalProbabilities
this.survivalProbabilities = (CreditDiscountFactors)newValue;
break;
default:
throw new NoSuchElementException("Unknown property: " + propertyName);
}
return(this);
}
public virtual void test_of_constant_interface()
{
IsdaCreditDiscountFactors test = (IsdaCreditDiscountFactors)CreditDiscountFactors.of(USD, VALUATION, CONST_CURVE);
assertEquals(test.Currency, USD);
assertEquals(test.Curve, CONST_CURVE);
assertEquals(test.DayCount, ACT_365L);
assertEquals(test.ParameterCount, 1);
assertEquals(test.getParameter(0), RATE_SINGLE);
assertEquals(test.ParameterKeys, DoubleArray.of(TIME_SINGLE));
assertEquals(test.getParameterMetadata(0), SimpleCurveParameterMetadata.of(METADATA.XValueType, TIME_SINGLE));
assertEquals(test.ValuationDate, VALUATION);
assertEquals(test.findData(CONST_CURVE.Name), CONST_CURVE);
assertEquals(test.findData(CurveName.of("Rubbish")), null);
assertEquals(test.toDiscountFactors(), ZeroRateDiscountFactors.of(USD, VALUATION, CONST_CURVE));
assertEquals(test.IsdaCompliant, true);
}
// extract CDS index trades from credit curve
private ImmutableList <ResolvedCdsIndexTrade> getBucketCdsIndex(ResolvedCdsIndex product, CreditRatesProvider ratesProvider)
{
CreditDiscountFactors creditCurve = ratesProvider.survivalProbabilities(product.CdsIndexId, product.Currency).SurvivalProbabilities;
int nNodes = creditCurve.ParameterCount;
ImmutableList.Builder <ResolvedCdsIndexTrade> builder = ImmutableList.builder();
for (int i = 0; i < nNodes; ++i)
{
ParameterMetadata metadata = creditCurve.getParameterMetadata(i);
ArgChecker.isTrue(metadata is ResolvedTradeParameterMetadata, "ParameterMetadata of credit curve must be ResolvedTradeParameterMetadata");
ResolvedTradeParameterMetadata tradeMetadata = (ResolvedTradeParameterMetadata)metadata;
ResolvedTrade trade = tradeMetadata.Trade;
ArgChecker.isTrue(trade is ResolvedCdsIndexTrade, "ResolvedTrade must be ResolvedCdsIndexTrade");
builder.add((ResolvedCdsIndexTrade)trade);
}
return(builder.build());
}
//-------------------------------------------------------------------------
public ImmutableCreditRatesProvider toImmutableCreditRatesProvider()
{
LocalDate valuationDate = ValuationDate;
// credit curves
IDictionary <Pair <StandardId, Currency>, LegalEntitySurvivalProbabilities> creditCurves = new Dictionary <Pair <StandardId, Currency>, LegalEntitySurvivalProbabilities>();
foreach (Pair <StandardId, Currency> pair in lookup.CreditCurveIds.Keys)
{
CurveId curveId = lookup.CreditCurveIds.get(pair);
if (marketData.containsValue(curveId))
{
Curve curve = marketData.getValue(curveId);
CreditDiscountFactors survivalProbabilities = CreditDiscountFactors.of(pair.Second, valuationDate, curve);
creditCurves[pair] = LegalEntitySurvivalProbabilities.of(pair.First, survivalProbabilities);
}
}
// discount curves
IDictionary <Currency, CreditDiscountFactors> discountCurves = new Dictionary <Currency, CreditDiscountFactors>();
foreach (Currency currency in lookup.DiscountCurveIds.Keys)
{
CurveId curveId = lookup.DiscountCurveIds.get(currency);
if (marketData.containsValue(curveId))
{
Curve curve = marketData.getValue(curveId);
discountCurves[currency] = CreditDiscountFactors.of(currency, valuationDate, curve);
}
}
// recovery rate curves
IDictionary <StandardId, RecoveryRates> recoveryRateCurves = new Dictionary <StandardId, RecoveryRates>();
foreach (StandardId legalEntityId in lookup.RecoveryRateCurveIds.Keys)
{
CurveId curveId = lookup.RecoveryRateCurveIds.get(legalEntityId);
if (marketData.containsValue(curveId))
{
Curve curve = marketData.getValue(curveId);
RecoveryRates recoveryRate = RecoveryRates.of(legalEntityId, valuationDate, curve);
recoveryRateCurves[legalEntityId] = recoveryRate;
}
}
// build result
return(ImmutableCreditRatesProvider.builder().valuationDate(valuationDate).creditCurves(creditCurves).discountCurves(discountCurves).recoveryRateCurves(recoveryRateCurves).build());
}
public CurrencyParameterSensitivity singleDiscountCurveParameterSensitivity(PointSensitivities pointSensitivities, Currency currency)
{
CurrencyParameterSensitivities sens = CurrencyParameterSensitivities.empty();
foreach (PointSensitivity point in pointSensitivities.Sensitivities)
{
if (point is ZeroRateSensitivity)
{
ZeroRateSensitivity pt = (ZeroRateSensitivity)point;
if (pt.Currency.Equals(currency))
{
CreditDiscountFactors factors = discountFactors(pt.CurveCurrency);
sens = sens.combinedWith(factors.parameterSensitivity(pt));
}
}
}
ArgChecker.isTrue(sens.size() == 1, "sensitivity must be unique");
return(sens.Sensitivities.get(0));
}
public virtual void test_of_interface()
{
IsdaCreditDiscountFactors test = (IsdaCreditDiscountFactors)CreditDiscountFactors.of(USD, VALUATION, CURVE);
assertEquals(test.Currency, USD);
assertEquals(test.Curve, CURVE);
assertEquals(test.DayCount, ACT_365F);
assertEquals(test.ParameterCount, RATE.size());
assertEquals(test.getParameter(3), RATE.get(3));
assertEquals(test.getParameter(1), RATE.get(1));
assertEquals(test.ParameterKeys, TIME);
assertEquals(test.getParameterMetadata(4), SimpleCurveParameterMetadata.of(METADATA.XValueType, TIME.get(4)));
assertEquals(test.getParameterMetadata(6), SimpleCurveParameterMetadata.of(METADATA.XValueType, TIME.get(6)));
assertEquals(test.ValuationDate, VALUATION);
assertEquals(test.findData(CURVE.Name), CURVE);
assertEquals(test.findData(CurveName.of("Rubbish")), null);
assertEquals(test.toDiscountFactors(), ZeroRateDiscountFactors.of(USD, VALUATION, CURVE));
assertEquals(test.IsdaCompliant, true);
}
//-------------------------------------------------------------------------
public CurrencyParameterSensitivities parameterSensitivity(PointSensitivities pointSensitivities)
{
CurrencyParameterSensitivities sens = CurrencyParameterSensitivities.empty();
foreach (PointSensitivity point in pointSensitivities.Sensitivities)
{
if (point is CreditCurveZeroRateSensitivity)
{
CreditCurveZeroRateSensitivity pt = (CreditCurveZeroRateSensitivity)point;
LegalEntitySurvivalProbabilities factors = survivalProbabilities(pt.LegalEntityId, pt.CurveCurrency);
sens = sens.combinedWith(factors.parameterSensitivity(pt));
}
else if (point is ZeroRateSensitivity)
{
ZeroRateSensitivity pt = (ZeroRateSensitivity)point;
CreditDiscountFactors factors = discountFactors(pt.CurveCurrency);
sens = sens.combinedWith(factors.parameterSensitivity(pt));
}
}
return(sens);
}
/// <summary>
/// The par spread quotes are converted to points upfronts or quoted spreads.
/// <para>
/// The relevant discount curve and recovery rate curve must be stored in {@code ratesProvider}.
/// The credit curve is internally calibrated to par spread values.
/// </para>
/// <para>
/// {@code trades} must be sorted in ascending order in maturity and coherent to {@code quotes}.
/// </para>
/// <para>
/// The resultant quote is specified by {@code targetConvention}.
///
/// </para>
/// </summary>
/// <param name="trades"> the trades </param>
/// <param name="quotes"> the quotes </param>
/// <param name="ratesProvider"> the rates provider </param>
/// <param name="targetConvention"> the target convention </param>
/// <param name="refData"> the reference data </param>
/// <returns> the quotes </returns>
public virtual IList <CdsQuote> quotesFromParSpread(IList <ResolvedCdsTrade> trades, IList <CdsQuote> quotes, CreditRatesProvider ratesProvider, CdsQuoteConvention targetConvention, ReferenceData refData)
{
ArgChecker.noNulls(trades, "trades");
ArgChecker.noNulls(quotes, "quotes");
ArgChecker.notNull(ratesProvider, "ratesProvider");
ArgChecker.notNull(targetConvention, "targetConvention");
ArgChecker.notNull(refData, "refData");
int nNodes = trades.Count;
ArgChecker.isTrue(quotes.Count == nNodes, "trades and quotes must be the same size");
quotes.ForEach(q => ArgChecker.isTrue(q.QuoteConvention.Equals(CdsQuoteConvention.PAR_SPREAD), "quote must be par spread"));
//JAVA TO C# CONVERTER TODO TASK: Most Java stream collectors are not converted by Java to C# Converter:
IEnumerator <StandardId> legalEntities = trades.Select(t => t.Product.LegalEntityId).collect(Collectors.toSet()).GetEnumerator();
//JAVA TO C# CONVERTER TODO TASK: Java iterators are only converted within the context of 'while' and 'for' loops:
StandardId legalEntityId = legalEntities.next();
//JAVA TO C# CONVERTER TODO TASK: Java iterators are only converted within the context of 'while' and 'for' loops:
ArgChecker.isFalse(legalEntities.hasNext(), "legal entity must be common to trades");
//JAVA TO C# CONVERTER TODO TASK: Most Java stream collectors are not converted by Java to C# Converter:
IEnumerator <Currency> currencies = trades.Select(t => t.Product.Currency).collect(Collectors.toSet()).GetEnumerator();
//JAVA TO C# CONVERTER TODO TASK: Java iterators are only converted within the context of 'while' and 'for' loops:
Currency currency = currencies.next();
//JAVA TO C# CONVERTER TODO TASK: Java iterators are only converted within the context of 'while' and 'for' loops:
ArgChecker.isFalse(currencies.hasNext(), "currency must be common to trades");
LocalDate valuationDate = ratesProvider.ValuationDate;
CreditDiscountFactors discountFactors = ratesProvider.discountFactors(currency);
RecoveryRates recoveryRates = ratesProvider.recoveryRates(legalEntityId);
NodalCurve creditCurve = calibrator.calibrate(trades, DoubleArray.of(nNodes, q => quotes[q].QuotedValue), DoubleArray.filled(nNodes), CurveName.of("temp"), valuationDate, discountFactors, recoveryRates, refData);
CreditRatesProvider ratesProviderNew = ratesProvider.toImmutableCreditRatesProvider().toBuilder().creditCurves(ImmutableMap.of(Pair.of(legalEntityId, currency), LegalEntitySurvivalProbabilities.of(legalEntityId, IsdaCreditDiscountFactors.of(currency, valuationDate, creditCurve)))).build();
System.Func <ResolvedCdsTrade, CdsQuote> quoteValueFunction = createQuoteValueFunction(ratesProviderNew, targetConvention, refData);
//JAVA TO C# CONVERTER TODO TASK: Most Java stream collectors are not converted by Java to C# Converter:
ImmutableList <CdsQuote> result = trades.Select(c => quoteValueFunction(c)).collect(Collectors.collectingAndThen(Collectors.toList(), ImmutableList.copyOf));
return(result);
}
// computes protection leg pv per unit notional, without loss-given-default rate multiplied
internal virtual double protectionFull(ResolvedCds cds, CreditDiscountFactors discountFactors, LegalEntitySurvivalProbabilities survivalProbabilities, LocalDate referenceDate, LocalDate effectiveStartDate)
{
DoubleArray integrationSchedule = DoublesScheduleGenerator.getIntegrationsPoints(discountFactors.relativeYearFraction(effectiveStartDate), discountFactors.relativeYearFraction(cds.ProtectionEndDate), discountFactors.ParameterKeys, survivalProbabilities.ParameterKeys);
double pv = 0d;
double ht0 = survivalProbabilities.zeroRate(integrationSchedule.get(0)) * integrationSchedule.get(0);
double rt0 = discountFactors.zeroRate(integrationSchedule.get(0)) * integrationSchedule.get(0);
double b0 = Math.Exp(-ht0 - rt0);
int n = integrationSchedule.size();
for (int i = 1; i < n; ++i)
{
double ht1 = survivalProbabilities.zeroRate(integrationSchedule.get(i)) * integrationSchedule.get(i);
double rt1 = discountFactors.zeroRate(integrationSchedule.get(i)) * integrationSchedule.get(i);
double b1 = Math.Exp(-ht1 - rt1);
double dht = ht1 - ht0;
double drt = rt1 - rt0;
double dhrt = dht + drt;
// The formula has been modified from ISDA (but is equivalent) to avoid log(exp(x)) and explicitly
// calculating the time step - it also handles the limit
double dPV = 0d;
if (Math.Abs(dhrt) < SMALL)
{
dPV = dht * b0 * epsilon(-dhrt);
}
else
{
dPV = (b0 - b1) * dht / dhrt;
}
pv += dPV;
ht0 = ht1;
rt0 = rt1;
b0 = b1;
}
// roll to the cash settle date
double df = discountFactors.discountFactor(referenceDate);
return(pv / df);
}
// computes risky annuity
internal virtual double riskyAnnuity(ResolvedCds cds, CreditDiscountFactors discountFactors, LegalEntitySurvivalProbabilities survivalProbabilities, LocalDate referenceDate, LocalDate stepinDate, LocalDate effectiveStartDate, PriceType priceType)
{
double pv = 0d;
foreach (CreditCouponPaymentPeriod coupon in cds.PaymentPeriods)
{
if (stepinDate.isBefore(coupon.EndDate))
{
double q = survivalProbabilities.survivalProbability(coupon.EffectiveEndDate);
double p = discountFactors.discountFactor(coupon.PaymentDate);
pv += coupon.YearFraction * p * q;
}
}
if (cds.PaymentOnDefault.AccruedInterest)
{
// This is needed so that the code is consistent with ISDA C when the Markit `fix' is used.
LocalDate start = cds.PaymentPeriods.size() == 1 ? effectiveStartDate : cds.AccrualStartDate;
DoubleArray integrationSchedule = DoublesScheduleGenerator.getIntegrationsPoints(discountFactors.relativeYearFraction(start), discountFactors.relativeYearFraction(cds.ProtectionEndDate), discountFactors.ParameterKeys, survivalProbabilities.ParameterKeys);
foreach (CreditCouponPaymentPeriod coupon in cds.PaymentPeriods)
{
pv += singlePeriodAccrualOnDefault(coupon, effectiveStartDate, integrationSchedule, discountFactors, survivalProbabilities);
}
}
// roll to the cash settle date
double df = discountFactors.discountFactor(referenceDate);
pv /= df;
if (priceType.CleanPrice)
{
pv -= cds.accruedYearFraction(stepinDate);
}
return(pv);
}
//-------------------------------------------------------------------------
/// <summary>
/// Creates an instance.
/// </summary>
/// <param name="legalEntityId"> the legal entity ID </param>
/// <param name="survivalProbabilities"> the survival probabilities </param>
/// <returns> the instance </returns>
public static LegalEntitySurvivalProbabilities of(StandardId legalEntityId, CreditDiscountFactors survivalProbabilities)
{
return(new LegalEntitySurvivalProbabilities(legalEntityId, survivalProbabilities));
}
//-------------------------------------------------------------------------
// computes protection leg pv per unit notional
private double protectionLeg(ResolvedCds cds, CreditDiscountFactors discountFactors, LegalEntitySurvivalProbabilities survivalProbabilities, LocalDate referenceDate, LocalDate effectiveStartDate, double recoveryRate)
{
double protectionFull = this.protectionFull(cds, discountFactors, survivalProbabilities, referenceDate, effectiveStartDate);
return((1d - recoveryRate) * protectionFull);
}
internal virtual PointSensitivityBuilder riskyAnnuitySensitivity(ResolvedCds cds, CreditDiscountFactors discountFactors, LegalEntitySurvivalProbabilities survivalProbabilities, LocalDate referenceDate, LocalDate stepinDate, LocalDate effectiveStartDate)
{
double pv = 0d;
PointSensitivityBuilder pvSensi = PointSensitivityBuilder.none();
foreach (CreditCouponPaymentPeriod coupon in cds.PaymentPeriods)
{
if (stepinDate.isBefore(coupon.EndDate))
{
double q = survivalProbabilities.survivalProbability(coupon.EffectiveEndDate);
PointSensitivityBuilder qSensi = survivalProbabilities.zeroRatePointSensitivity(coupon.EffectiveEndDate);
double p = discountFactors.discountFactor(coupon.PaymentDate);
PointSensitivityBuilder pSensi = discountFactors.zeroRatePointSensitivity(coupon.PaymentDate);
pv += coupon.YearFraction * p * q;
pvSensi = pvSensi.combinedWith(pSensi.multipliedBy(coupon.YearFraction * q).combinedWith(qSensi.multipliedBy(coupon.YearFraction * p)));
}
}
if (cds.PaymentOnDefault.AccruedInterest)
{
// This is needed so that the code is consistent with ISDA C when the Markit `fix' is used.
LocalDate start = cds.PaymentPeriods.size() == 1 ? effectiveStartDate : cds.AccrualStartDate;
DoubleArray integrationSchedule = DoublesScheduleGenerator.getIntegrationsPoints(discountFactors.relativeYearFraction(start), discountFactors.relativeYearFraction(cds.ProtectionEndDate), discountFactors.ParameterKeys, survivalProbabilities.ParameterKeys);
foreach (CreditCouponPaymentPeriod coupon in cds.PaymentPeriods)
{
Pair <double, PointSensitivityBuilder> pvAndSensi = singlePeriodAccrualOnDefaultSensitivity(coupon, effectiveStartDate, integrationSchedule, discountFactors, survivalProbabilities);
pv += pvAndSensi.First;
pvSensi = pvSensi.combinedWith(pvAndSensi.Second);
}
}
double df = discountFactors.discountFactor(referenceDate);
PointSensitivityBuilder dfSensi = discountFactors.zeroRatePointSensitivity(referenceDate).multipliedBy(-pv / (df * df));
pvSensi = pvSensi.multipliedBy(1d / df);
return(dfSensi.combinedWith(pvSensi));
}
// computes accrual-on-default pv per unit notional for a single payment period
private double singlePeriodAccrualOnDefault(CreditCouponPaymentPeriod coupon, LocalDate effectiveStartDate, DoubleArray integrationSchedule, CreditDiscountFactors discountFactors, LegalEntitySurvivalProbabilities survivalProbabilities)
{
LocalDate start = coupon.EffectiveStartDate.isBefore(effectiveStartDate) ? effectiveStartDate : coupon.EffectiveStartDate;
if (!start.isBefore(coupon.EffectiveEndDate))
{
return(0d); // this coupon has already expired
}
DoubleArray knots = DoublesScheduleGenerator.truncateSetInclusive(discountFactors.relativeYearFraction(start), discountFactors.relativeYearFraction(coupon.EffectiveEndDate), integrationSchedule);
double t0Knot = knots.get(0);
double ht0 = survivalProbabilities.zeroRate(t0Knot) * t0Knot;
double rt0 = discountFactors.zeroRate(t0Knot) * t0Knot;
double b0 = Math.Exp(-rt0 - ht0);
double effStart = discountFactors.relativeYearFraction(coupon.EffectiveStartDate);
double t0 = t0Knot - effStart + omega;
double pv = 0d;
//JAVA TO C# CONVERTER WARNING: The original Java variable was marked 'final':
//ORIGINAL LINE: final int nItems = knots.size();
int nItems = knots.size();
for (int j = 1; j < nItems; ++j)
{
double t = knots.get(j);
double ht1 = survivalProbabilities.zeroRate(t) * t;
double rt1 = discountFactors.zeroRate(t) * t;
double b1 = Math.Exp(-rt1 - ht1);
double dt = knots.get(j) - knots.get(j - 1);
double dht = ht1 - ht0;
double drt = rt1 - rt0;
double dhrt = dht + drt;
double tPV;
if (formula == AccrualOnDefaultFormula.MARKIT_FIX)
{
if (Math.Abs(dhrt) < SMALL)
{
tPV = dht * dt * b0 * Epsilon.epsilonP(-dhrt);
}
else
{
tPV = dht * dt / dhrt * ((b0 - b1) / dhrt - b1);
}
}
else
{
double t1 = t - effStart + omega;
if (Math.Abs(dhrt) < SMALL)
{
tPV = dht * b0 * (t0 * epsilon(-dhrt) + dt * Epsilon.epsilonP(-dhrt));
}
else
{
tPV = dht / dhrt * (t0 * b0 - t1 * b1 + dt / dhrt * (b0 - b1));
}
t0 = t1;
}
pv += tPV;
ht0 = ht1;
rt0 = rt1;
b0 = b1;
}
double yearFractionCurve = discountFactors.DayCount.relativeYearFraction(coupon.StartDate, coupon.EndDate);
return(coupon.YearFraction * pv / yearFractionCurve);
}
//-------------------------------------------------------------------------
internal virtual PointSensitivityBuilder protectionLegSensitivity(ResolvedCds cds, CreditDiscountFactors discountFactors, LegalEntitySurvivalProbabilities survivalProbabilities, LocalDate referenceDate, LocalDate effectiveStartDate, double recoveryRate)
{
DoubleArray integrationSchedule = DoublesScheduleGenerator.getIntegrationsPoints(discountFactors.relativeYearFraction(effectiveStartDate), discountFactors.relativeYearFraction(cds.ProtectionEndDate), discountFactors.ParameterKeys, survivalProbabilities.ParameterKeys);
int n = integrationSchedule.size();
double[] dht = new double[n - 1];
double[] drt = new double[n - 1];
double[] dhrt = new double[n - 1];
double[] p = new double[n];
double[] q = new double[n];
// pv
double pv = 0d;
double ht0 = survivalProbabilities.zeroRate(integrationSchedule.get(0)) * integrationSchedule.get(0);
double rt0 = discountFactors.zeroRate(integrationSchedule.get(0)) * integrationSchedule.get(0);
p[0] = Math.Exp(-rt0);
q[0] = Math.Exp(-ht0);
double b0 = p[0] * q[0];
for (int i = 1; i < n; ++i)
{
double ht1 = survivalProbabilities.zeroRate(integrationSchedule.get(i)) * integrationSchedule.get(i);
double rt1 = discountFactors.zeroRate(integrationSchedule.get(i)) * integrationSchedule.get(i);
p[i] = Math.Exp(-rt1);
q[i] = Math.Exp(-ht1);
double b1 = p[i] * q[i];
dht[i - 1] = ht1 - ht0;
drt[i - 1] = rt1 - rt0;
dhrt[i - 1] = dht[i - 1] + drt[i - 1];
double dPv = 0d;
if (Math.Abs(dhrt[i - 1]) < SMALL)
{
double eps = epsilon(-dhrt[i - 1]);
dPv = dht[i - 1] * b0 * eps;
}
else
{
dPv = (b0 - b1) * dht[i - 1] / dhrt[i - 1];
}
pv += dPv;
ht0 = ht1;
rt0 = rt1;
b0 = b1;
}
double df = discountFactors.discountFactor(referenceDate);
// pv sensitivity
double factor = (1d - recoveryRate) / df;
double eps0 = computeExtendedEpsilon(-dhrt[0], p[1], q[1], p[0], q[0]);
PointSensitivityBuilder pvSensi = discountFactors.zeroRatePointSensitivity(integrationSchedule.get(0)).multipliedBy(-dht[0] * q[0] * eps0 * factor);
pvSensi = pvSensi.combinedWith(survivalProbabilities.zeroRatePointSensitivity(integrationSchedule.get(0)).multipliedBy(factor * (drt[0] * p[0] * eps0 + p[0])));
for (int i = 1; i < n - 1; ++i)
{
double epsp = computeExtendedEpsilon(-dhrt[i], p[i + 1], q[i + 1], p[i], q[i]);
double epsm = computeExtendedEpsilon(dhrt[i - 1], p[i - 1], q[i - 1], p[i], q[i]);
PointSensitivityBuilder pSensi = discountFactors.zeroRatePointSensitivity(integrationSchedule.get(i)).multipliedBy(factor * (-dht[i] * q[i] * epsp - dht[i - 1] * q[i] * epsm));
PointSensitivityBuilder qSensi = survivalProbabilities.zeroRatePointSensitivity(integrationSchedule.get(i)).multipliedBy(factor * (drt[i - 1] * p[i] * epsm + drt[i] * p[i] * epsp));
pvSensi = pvSensi.combinedWith(pSensi).combinedWith(qSensi);
}
if (n > 1)
{
double epsLast = computeExtendedEpsilon(dhrt[n - 2], p[n - 2], q[n - 2], p[n - 1], q[n - 1]);
pvSensi = pvSensi.combinedWith(discountFactors.zeroRatePointSensitivity(integrationSchedule.get(n - 1)).multipliedBy(-dht[n - 2] * q[n - 1] * epsLast * factor));
pvSensi = pvSensi.combinedWith(survivalProbabilities.zeroRatePointSensitivity(integrationSchedule.get(n - 1)).multipliedBy(factor * (drt[n - 2] * p[n - 1] * epsLast - p[n - 1])));
}
PointSensitivityBuilder dfSensi = discountFactors.zeroRatePointSensitivity(referenceDate).multipliedBy(-pv * factor / df);
return(dfSensi.combinedWith(pvSensi));
}
private System.Func <double, double> getPriceFunction(int index, ResolvedCdsTrade cds, double flactionalSpread, double pointsUpfront, LocalDate valuationDate, NodalCurve creditCurve, CreditDiscountFactors discountFactors, RecoveryRates recoveryRates, ReferenceData refData)
{
ResolvedCds cdsProduct = cds.Product;
Currency currency = cdsProduct.Currency;
StandardId legalEntityId = cdsProduct.LegalEntityId;
Pair <StandardId, Currency> pair = Pair.of(legalEntityId, currency);
ImmutableCreditRatesProvider ratesbase = ImmutableCreditRatesProvider.builder().valuationDate(valuationDate).discountCurves(ImmutableMap.of(currency, discountFactors)).recoveryRateCurves(ImmutableMap.of(legalEntityId, recoveryRates)).build();
System.Func <double, double> func = (double?x) =>
{
NodalCurve tempCreditCurve = creditCurve.withParameter(index, x.Value);
ImmutableCreditRatesProvider rates = ratesbase.toBuilder().creditCurves(ImmutableMap.of(pair, LegalEntitySurvivalProbabilities.of(legalEntityId, IsdaCreditDiscountFactors.of(currency, valuationDate, tempCreditCurve)))).build();
double price = TradePricer.price(cds, rates, flactionalSpread, PriceType.CLEAN, refData);
return(price - pointsUpfront);
};
return(func);
}
//-------------------------------------------------------------------------
public override NodalCurve calibrate(IList <ResolvedCdsTrade> calibrationCDSs, DoubleArray flactionalSpreads, DoubleArray pointsUpfront, CurveName name, LocalDate valuationDate, CreditDiscountFactors discountFactors, RecoveryRates recoveryRates, ReferenceData refData)
{
int n = calibrationCDSs.Count;
double[] guess = new double[n];
double[] t = new double[n];
double[] lgd = new double[n];
for (int i = 0; i < n; i++)
{
LocalDate endDate = calibrationCDSs[i].Product.ProtectionEndDate;
t[i] = discountFactors.relativeYearFraction(endDate);
lgd[i] = 1d - recoveryRates.recoveryRate(endDate);
guess[i] = (flactionalSpreads.get(i) + pointsUpfront.get(i) / t[i]) / lgd[i];
}
DoubleArray times = DoubleArray.ofUnsafe(t);
CurveMetadata baseMetadata = DefaultCurveMetadata.builder().xValueType(ValueType.YEAR_FRACTION).yValueType(ValueType.ZERO_RATE).curveName(name).dayCount(discountFactors.DayCount).build();
NodalCurve creditCurve = n == 1 ? ConstantNodalCurve.of(baseMetadata, t[0], guess[0]) : InterpolatedNodalCurve.of(baseMetadata, times, DoubleArray.ofUnsafe(guess), CurveInterpolators.PRODUCT_LINEAR, CurveExtrapolators.FLAT, CurveExtrapolators.PRODUCT_LINEAR);
for (int i = 0; i < n; i++)
{
ResolvedCds cds = calibrationCDSs[i].Product;
LocalDate stepinDate = cds.StepinDateOffset.adjust(valuationDate, refData);
LocalDate effectiveStartDate = cds.calculateEffectiveStartDate(stepinDate);
LocalDate settlementDate = calibrationCDSs[i].Info.SettlementDate.orElse(cds.SettlementDateOffset.adjust(valuationDate, refData));
double accrued = cds.accruedYearFraction(stepinDate);
Pricer pricer = new Pricer(this, cds, discountFactors, times, flactionalSpreads.get(i), pointsUpfront.get(i), lgd[i], stepinDate, effectiveStartDate, settlementDate, accrued);
System.Func <double, double> func = pricer.getPointFunction(i, creditCurve);
switch (ArbitrageHandling)
{
case IGNORE:
{
try
{
double[] bracket = BRACKETER.getBracketedPoints(func, 0.8 * guess[i], 1.25 * guess[i], double.NegativeInfinity, double.PositiveInfinity);
double zeroRate = bracket[0] > bracket[1] ? ROOTFINDER.getRoot(func, bracket[1], bracket[0]) : ROOTFINDER.getRoot(func, bracket[0], bracket[1]); //Negative guess handled
creditCurve = creditCurve.withParameter(i, zeroRate);
}
//JAVA TO C# CONVERTER WARNING: 'final' catch parameters are not available in C#:
//ORIGINAL LINE: catch (final com.opengamma.strata.math.MathException e)
catch (MathException e)
{ //handling bracketing failure due to small survival probability
if (Math.Abs(func(creditCurve.YValues.get(i - 1))) < 1.e-12)
{
creditCurve = creditCurve.withParameter(i, creditCurve.YValues.get(i - 1));
}
else
{
throw new MathException(e);
}
}
break;
}
case FAIL:
{
//JAVA TO C# CONVERTER WARNING: The original Java variable was marked 'final':
//ORIGINAL LINE: final double minValue = i == 0 ? 0d : creditCurve.getYValues().get(i - 1) * creditCurve.getXValues().get(i - 1) / creditCurve.getXValues().get(i);
double minValue = i == 0 ? 0d : creditCurve.YValues.get(i - 1) * creditCurve.XValues.get(i - 1) / creditCurve.XValues.get(i);
if (i > 0 && func(minValue) > 0.0)
{ //can never fail on the first spread
//JAVA TO C# CONVERTER WARNING: The original Java variable was marked 'final':
//ORIGINAL LINE: final StringBuilder msg = new StringBuilder();
StringBuilder msg = new StringBuilder();
if (pointsUpfront.get(i) == 0.0)
{
msg.Append("The par spread of " + flactionalSpreads.get(i) + " at index " + i);
}
else
{
msg.Append("The premium of " + flactionalSpreads.get(i) + "and points up-front of " + pointsUpfront.get(i) + " at index " + i);
}
msg.Append(" is an arbitrage; cannot fit a curve with positive forward hazard rate. ");
throw new System.ArgumentException(msg.ToString());
}
guess[i] = Math.Max(minValue, guess[i]);
double[] bracket = BRACKETER.getBracketedPoints(func, guess[i], 1.2 * guess[i], minValue, double.PositiveInfinity);
double zeroRate = ROOTFINDER.getRoot(func, bracket[0], bracket[1]).Value;
creditCurve = creditCurve.withParameter(i, zeroRate);
break;
}
case ZERO_HAZARD_RATE:
{
//JAVA TO C# CONVERTER WARNING: The original Java variable was marked 'final':
//ORIGINAL LINE: final double minValue = i == 0 ? 0.0 : creditCurve.getYValues().get(i - 1) * creditCurve.getXValues().get(i - 1) / creditCurve.getXValues().get(i);
double minValue = i == 0 ? 0.0 : creditCurve.YValues.get(i - 1) * creditCurve.XValues.get(i - 1) / creditCurve.XValues.get(i);
if (i > 0 && func(minValue) > 0.0)
{ //can never fail on the first spread
creditCurve = creditCurve.withParameter(i, minValue);
}
else
{
guess[i] = Math.Max(minValue, guess[i]);
//JAVA TO C# CONVERTER WARNING: The original Java variable was marked 'final':
//ORIGINAL LINE: final double[] bracket = BRACKETER.getBracketedPoints(func, guess[i], 1.2 * guess[i], minValue, Double.POSITIVE_INFINITY);
double[] bracket = BRACKETER.getBracketedPoints(func, guess[i], 1.2 * guess[i], minValue, double.PositiveInfinity);
//JAVA TO C# CONVERTER WARNING: The original Java variable was marked 'final':
//ORIGINAL LINE: final double zeroRate = ROOTFINDER.getRoot(func, bracket[0], bracket[1]);
double zeroRate = ROOTFINDER.getRoot(func, bracket[0], bracket[1]).Value;
creditCurve = creditCurve.withParameter(i, zeroRate);
}
break;
}
default:
throw new System.ArgumentException("unknown case " + ArbitrageHandling);
}
}
return(creditCurve);
}
public Pricer(FastCreditCurveCalibrator outerInstance, ResolvedCds nodeCds, CreditDiscountFactors yieldCurve, DoubleArray creditCurveKnots, double fractionalSpread, double pointsUpfront, double lgd, LocalDate stepinDate, LocalDate effectiveStartDate, LocalDate settlementDate, double accruedYearFraction)
{
this.outerInstance = outerInstance;
accYearFraction = accruedYearFraction;
cds = nodeCds;
fracSpread = fractionalSpread;
puf = pointsUpfront;
productEffectiveStart = yieldCurve.relativeYearFraction(effectiveStartDate);
double protectionEnd = yieldCurve.relativeYearFraction(cds.ProtectionEndDate);
// protection leg
proLegIntPoints = DoublesScheduleGenerator.getIntegrationsPoints(productEffectiveStart, protectionEnd, yieldCurve.ParameterKeys, creditCurveKnots).toArray();
nProPoints = proLegIntPoints.Length;
valuationDF = yieldCurve.discountFactor(settlementDate);
lgdDF = lgd / valuationDF;
proYieldCurveRT = new double[nProPoints];
proDF = new double[nProPoints];
for (int i = 0; i < nProPoints; i++)
{
proYieldCurveRT[i] = yieldCurve.zeroRate(proLegIntPoints[i]) * proLegIntPoints[i];
proDF[i] = Math.Exp(-proYieldCurveRT[i]);
}
// premium leg
nPayments = cds.PaymentPeriods.size();
paymentDF = new double[nPayments];
int indexTmp = -1;
for (int i = 0; i < nPayments; i++)
{
if (stepinDate.isBefore(cds.PaymentPeriods.get(i).EndDate))
{
paymentDF[i] = yieldCurve.discountFactor(cds.PaymentPeriods.get(i).PaymentDate);
}
else
{
indexTmp = i;
}
}
startPeriodIndex = indexTmp + 1;
// accrual on default
if (cds.PaymentOnDefault.AccruedInterest)
{
LocalDate tmp = nPayments == 1 ? effectiveStartDate : cds.AccrualStartDate;
DoubleArray integrationSchedule = DoublesScheduleGenerator.getIntegrationsPoints(yieldCurve.relativeYearFraction(tmp), protectionEnd, yieldCurve.ParameterKeys, creditCurveKnots);
accRate = new double[nPayments];
offsetAccStart = new double[nPayments];
offsetAccEnd = new double[nPayments];
premLegIntPoints = new double[nPayments][];
premDF = new double[nPayments][];
rt = new double[nPayments][];
premDt = new double[nPayments][];
for (int i = startPeriodIndex; i < nPayments; i++)
{
CreditCouponPaymentPeriod coupon = cds.PaymentPeriods.get(i);
offsetAccStart[i] = yieldCurve.relativeYearFraction(coupon.EffectiveStartDate);
offsetAccEnd[i] = yieldCurve.relativeYearFraction(coupon.EffectiveEndDate);
accRate[i] = coupon.YearFraction / yieldCurve.DayCount.relativeYearFraction(coupon.StartDate, coupon.EndDate);
double start = Math.Max(productEffectiveStart, offsetAccStart[i]);
if (start >= offsetAccEnd[i])
{
continue;
}
premLegIntPoints[i] = DoublesScheduleGenerator.truncateSetInclusive(start, offsetAccEnd[i], integrationSchedule).toArray();
int n = premLegIntPoints[i].Length;
rt[i] = new double[n];
premDF[i] = new double[n];
for (int k = 0; k < n; k++)
{
rt[i][k] = yieldCurve.zeroRate(premLegIntPoints[i][k]) * premLegIntPoints[i][k];
premDF[i][k] = Math.Exp(-rt[i][k]);
}
premDt[i] = new double[n - 1];
for (int k = 1; k < n; k++)
{
//JAVA TO C# CONVERTER WARNING: The original Java variable was marked 'final':
//ORIGINAL LINE: final double dt = premLegIntPoints[i][k] - premLegIntPoints[i][k - 1];
double dt = premLegIntPoints[i][k] - premLegIntPoints[i][k - 1];
premDt[i][k - 1] = dt;
}
}
}
else
{
accRate = null;
offsetAccStart = null;
offsetAccEnd = null;
premDF = null;
premDt = null;
rt = null;
premLegIntPoints = null;
}
}
private Pair <double, PointSensitivityBuilder> singlePeriodAccrualOnDefaultSensitivity(CreditCouponPaymentPeriod coupon, LocalDate effectiveStartDate, DoubleArray integrationSchedule, CreditDiscountFactors discountFactors, LegalEntitySurvivalProbabilities survivalProbabilities)
{
LocalDate start = coupon.EffectiveStartDate.isBefore(effectiveStartDate) ? effectiveStartDate : coupon.EffectiveStartDate;
if (!start.isBefore(coupon.EffectiveEndDate))
{
return(Pair.of(0d, PointSensitivityBuilder.none())); //this coupon has already expired
}
DoubleArray knots = DoublesScheduleGenerator.truncateSetInclusive(discountFactors.relativeYearFraction(start), discountFactors.relativeYearFraction(coupon.EffectiveEndDate), integrationSchedule);
// pv
double pv = 0d;
//JAVA TO C# CONVERTER WARNING: The original Java variable was marked 'final':
//ORIGINAL LINE: final int nItems = knots.size();
int nItems = knots.size();
double[] dhrtBar = new double[nItems - 1];
double[] dhtBar = new double[nItems - 1];
double[] bBar = new double[nItems];
double[] p = new double[nItems];
double[] q = new double[nItems];
double t = knots.get(0);
double ht0 = survivalProbabilities.zeroRate(t) * t;
double rt0 = discountFactors.zeroRate(t) * t;
q[0] = Math.Exp(-ht0);
p[0] = Math.Exp(-rt0);
double b0 = q[0] * p[0];
double effStart = discountFactors.relativeYearFraction(coupon.EffectiveStartDate);
double t0 = t - effStart + omega;
for (int i = 1; i < nItems; ++i)
{
t = knots.get(i);
double ht1 = survivalProbabilities.zeroRate(t) * t;
double rt1 = discountFactors.zeroRate(t) * t;
q[i] = Math.Exp(-ht1);
p[i] = Math.Exp(-rt1);
double b1 = q[i] * p[i];
double dt = knots.get(i) - knots.get(i - 1);
double dht = ht1 - ht0;
double drt = rt1 - rt0;
double dhrt = dht + drt;
double tPv;
if (formula == AccrualOnDefaultFormula.MARKIT_FIX)
{
if (Math.Abs(dhrt) < SMALL)
{
double eps = epsilonP(-dhrt);
tPv = dht * dt * b0 * eps;
dhtBar[i - 1] = dt * b0 * eps;
dhrtBar[i - 1] = -dht *dt *b0 *epsilonPP(-dhrt);
bBar[i - 1] += dht * eps;
}
else
{
tPv = dht * dt / dhrt * ((b0 - b1) / dhrt - b1);
dhtBar[i - 1] = dt / dhrt * ((b0 - b1) / dhrt - b1);
dhrtBar[i - 1] = dht * dt / (dhrt * dhrt) * (b1 - 2d * (b0 - b1) / dhrt);
bBar[i - 1] += dht * dt / (dhrt * dhrt);
bBar[i] += -dht * dt / dhrt * (1d + 1d / dhrt);
}
}
else
{
double t1 = t - effStart + omega;
if (Math.Abs(dhrt) < SMALL)
{
double eps = epsilon(-dhrt);
double epsp = epsilonP(-dhrt);
tPv = dht * b0 * (t0 * eps + dt * epsp);
dhtBar[i - 1] = b0 * (t0 * eps + dt * epsp);
dhrtBar[i - 1] = -dht * b0 * (t0 * epsp + dt * epsilonPP(-dhrt));
bBar[i - 1] += dht * (t0 * eps + dt * epsp);
}
else
{
tPv = dht / dhrt * (t0 * b0 - t1 * b1 + dt / dhrt * (b0 - b1));
dhtBar[i - 1] = (t0 * b0 - t1 * b1 + dt / dhrt * (b0 - b1)) / dhrt;
dhrtBar[i - 1] = dht / (dhrt * dhrt) * (-2d * dt / dhrt * (b0 - b1) - t0 * b0 + t1 * b1);
bBar[i - 1] += dht / dhrt * (t0 + dt / dhrt);
bBar[i] += dht / dhrt * (-t1 - dt / dhrt);
}
t0 = t1;
}
pv += tPv;
ht0 = ht1;
rt0 = rt1;
b0 = b1;
}
double yfRatio = coupon.YearFraction / discountFactors.DayCount.relativeYearFraction(coupon.StartDate, coupon.EndDate);
// pv sensitivity
PointSensitivityBuilder qSensiFirst = survivalProbabilities.zeroRatePointSensitivity(knots.get(0)).multipliedBy(yfRatio * ((dhrtBar[0] + dhtBar[0]) / q[0] + bBar[0] * p[0]));
PointSensitivityBuilder pSensiFirst = discountFactors.zeroRatePointSensitivity(knots.get(0)).multipliedBy(yfRatio * (dhrtBar[0] / p[0] + bBar[0] * q[0]));
PointSensitivityBuilder pvSensi = pSensiFirst.combinedWith(qSensiFirst);
for (int i = 1; i < nItems - 1; ++i)
{
PointSensitivityBuilder qSensi = survivalProbabilities.zeroRatePointSensitivity(knots.get(i)).multipliedBy(yfRatio * (-(dhrtBar[i - 1] + dhtBar[i - 1]) / q[i] + (dhrtBar[i] + dhtBar[i]) / q[i] + bBar[i] * p[i]));
PointSensitivityBuilder pSensi = discountFactors.zeroRatePointSensitivity(knots.get(i)).multipliedBy(yfRatio * (-dhrtBar[i - 1] / p[i] + dhrtBar[i] / p[i] + bBar[i] * q[i]));
pvSensi = pvSensi.combinedWith(pSensi).combinedWith(qSensi);
}
if (nItems > 1)
{
PointSensitivityBuilder qSensiLast = survivalProbabilities.zeroRatePointSensitivity(knots.get(nItems - 1)).multipliedBy(yfRatio * (-(dhrtBar[nItems - 2] + dhtBar[nItems - 2]) / q[nItems - 1] + bBar[nItems - 1] * p[nItems - 1]));
PointSensitivityBuilder pSensiLast = discountFactors.zeroRatePointSensitivity(knots.get(nItems - 1)).multipliedBy(yfRatio * (-dhrtBar[nItems - 2] / p[nItems - 1] + bBar[nItems - 1] * q[nItems - 1]));
pvSensi = pvSensi.combinedWith(pSensiLast).combinedWith(qSensiLast);
}
return(Pair.of(yfRatio * pv, pvSensi));
}
//-------------------------------------------------------------------------
public override NodalCurve calibrate(IList <ResolvedCdsTrade> calibrationCDSs, DoubleArray premiums, DoubleArray pointsUpfront, CurveName name, LocalDate valuationDate, CreditDiscountFactors discountFactors, RecoveryRates recoveryRates, ReferenceData refData)
{
int n = calibrationCDSs.Count;
double[] guess = new double[n];
double[] t = new double[n];
double[] lgd = new double[n];
for (int i = 0; i < n; i++)
{
LocalDate endDate = calibrationCDSs[i].Product.ProtectionEndDate;
t[i] = discountFactors.relativeYearFraction(endDate);
lgd[i] = 1d - recoveryRates.recoveryRate(endDate);
guess[i] = (premiums.get(i) + pointsUpfront.get(i) / t[i]) / lgd[i];
}
DoubleArray times = DoubleArray.ofUnsafe(t);
CurveMetadata baseMetadata = DefaultCurveMetadata.builder().xValueType(ValueType.YEAR_FRACTION).yValueType(ValueType.ZERO_RATE).curveName(name).dayCount(discountFactors.DayCount).build();
NodalCurve creditCurve = n == 1 ? ConstantNodalCurve.of(baseMetadata, t[0], guess[0]) : InterpolatedNodalCurve.of(baseMetadata, times, DoubleArray.ofUnsafe(guess), CurveInterpolators.PRODUCT_LINEAR, CurveExtrapolators.FLAT, CurveExtrapolators.PRODUCT_LINEAR);
for (int i = 0; i < n; i++)
{
System.Func <double, double> func = getPriceFunction(i, calibrationCDSs[i], premiums.get(i), pointsUpfront.get(i), valuationDate, creditCurve, discountFactors, recoveryRates, refData);
double[] bracket = BRACKER.getBracketedPoints(func, 0.8 * guess[i], 1.25 * guess[i], 0.0, double.PositiveInfinity);
double zeroRate = bracket[0] > bracket[1] ? ROOTFINDER.getRoot(func, bracket[1], bracket[0]) : ROOTFINDER.getRoot(func, bracket[0], bracket[1]); //Negative guess handled
creditCurve = creditCurve.withParameter(i, zeroRate);
}
return(creditCurve);
}
private double[] getStandardQuoteForm(ResolvedCdsTrade calibrationCds, CdsQuote marketQuote, LocalDate valuationDate, CreditDiscountFactors discountFactors, RecoveryRates recoveryRates, bool computeJacobian, ReferenceData refData)
{
double[] res = new double[3];
res[2] = 1d;
if (marketQuote.QuoteConvention.Equals(CdsQuoteConvention.PAR_SPREAD))
{
res[0] = marketQuote.QuotedValue;
}
else if (marketQuote.QuoteConvention.Equals(CdsQuoteConvention.QUOTED_SPREAD))
{
double qSpread = marketQuote.QuotedValue;
CurveName curveName = CurveName.of("quoteConvertCurve");
NodalCurve tempCreditCurve = calibrate(ImmutableList.of(calibrationCds), DoubleArray.of(qSpread), DoubleArray.of(0d), curveName, valuationDate, discountFactors, recoveryRates, refData);
Currency currency = calibrationCds.Product.Currency;
StandardId legalEntityId = calibrationCds.Product.LegalEntityId;
ImmutableCreditRatesProvider rates = ImmutableCreditRatesProvider.builder().valuationDate(valuationDate).discountCurves(ImmutableMap.of(currency, discountFactors)).recoveryRateCurves(ImmutableMap.of(legalEntityId, recoveryRates)).creditCurves(ImmutableMap.of(Pair.of(legalEntityId, currency), LegalEntitySurvivalProbabilities.of(legalEntityId, IsdaCreditDiscountFactors.of(currency, valuationDate, tempCreditCurve)))).build();
res[0] = calibrationCds.Product.FixedRate;
res[1] = tradePricer.price(calibrationCds, rates, PriceType.CLEAN, refData);
if (computeJacobian)
{
CurrencyParameterSensitivities pufSensi = rates.parameterSensitivity(tradePricer.priceSensitivity(calibrationCds, rates, refData));
CurrencyParameterSensitivities spSensi = rates.parameterSensitivity(tradePricer.parSpreadSensitivity(calibrationCds, rates, refData));
res[2] = spSensi.getSensitivity(curveName, currency).Sensitivity.get(0) / pufSensi.getSensitivity(curveName, currency).Sensitivity.get(0);
}
}
else if (marketQuote.QuoteConvention.Equals(CdsQuoteConvention.POINTS_UPFRONT))
{
res[0] = calibrationCds.Product.FixedRate;
res[1] = marketQuote.QuotedValue;
}
else
{
throw new System.ArgumentException("Unknown CDSQuoteConvention type " + marketQuote.GetType());
}
return(res);
}
