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 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);
}
// 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);
}
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;
}
}
//-------------------------------------------------------------------------
public virtual void test_survivalProbability()
{
LegalEntitySurvivalProbabilities test = LegalEntitySurvivalProbabilities.of(LEGAL_ENTITY, DFS);
assertEquals(test.survivalProbability(DATE_AFTER), DFS.discountFactor(DATE_AFTER));
}
//-------------------------------------------------------------------------
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));
}
