public double rpv01(IsdaCompliantCreditCurve creditCurve, CdsPriceType cleanOrDirty) {
double pv = 0.0;
for (int i = 0; i < _nPayments; i++) {
CdsCoupon c = _cds.getCoupon(i);
double q = creditCurve.getDiscountFactor(c.getEffEnd());
pv += c.getYearFrac() * _paymentDF[i] * q;
}
if (_cds.isPayAccOnDefault()) {
double accPV = 0.0;
for (int i = 0; i < _nPayments; i++) {
accPV += calculateSinglePeriodAccrualOnDefault(i, creditCurve);
}
pv += accPV;
}
pv /= _valuationDF;
if (cleanOrDirty == CdsPriceType.CLEAN) {
pv -= _cds.getAccruedYearFraction();
}
return pv;
}
/**
* The bucked CS01 (or credit DV01) by shifting each implied par-spread in turn. This takes an
* extraneous yield curve and a credit curve and a set of bucket CDSs (CDSs with maturities equal
* to the bucket points). Par-spreads at the bucket maturities are implied from the credit curve.
* These spreads form pseudo market spreads to bootstraps a new credit (hazard) curve - the target
* CDS is then priced with this credit curve. This is then repeated with each spreads bumped in
* turn. The result is the vector of differences (bumped minus base price) divided by the bump
* amount.
*
* @param cds analytic description of a CDS traded at a certain time
* @param cdsCoupon The <b>fraction</b> spread of the CDS
* @param bucketCDSs these are the reference instruments that correspond to maturity buckets
* @param yieldCurve The yield (or discount) curve
* @param creditCurve the credit curve
* @param fracBumpAmount The fraction bump amount, so a 1pb bump is 1e-4
* @return The credit DV01
*/
public double[] bucketedCS01FromCreditCurve(
CdsAnalytic cds,
double cdsCoupon,
CdsAnalytic[] bucketCDSs,
IsdaCompliantYieldCurve yieldCurve,
IsdaCompliantCreditCurve creditCurve,
double fracBumpAmount) {
ArgChecker.notNull(cds, "cds");
ArgChecker.noNulls(bucketCDSs, "bucketCDSs");
ArgChecker.notNull(creditCurve, "creditCurve");
ArgChecker.notNull(yieldCurve, "yieldCurve");
ArgChecker.isTrue(Math.abs(fracBumpAmount) > 1e-10, "bump amount too small");
int n = bucketCDSs.length;
double[] impSpreads = new double[n];
double[] t = new double[n];
for (int i = 0; i < n; i++) {
impSpreads[i] = _pricer.parSpread(bucketCDSs[i], yieldCurve, creditCurve);
t[i] = bucketCDSs[i].getProtectionEnd();
if (i > 0) {
ArgChecker.isTrue(t[i] > t[i - 1], "buckets must be assending");
}
}
int index = Arrays.binarySearch(t, cds.getProtectionEnd());
if (index < 0) {
index = -1 - index;
}
index = Math.min(index, n - 1);
IsdaCompliantCreditCurve baseCurve =
_curveBuilder.calibrateCreditCurve(bucketCDSs, impSpreads, yieldCurve);
double basePrice = _pricer.pv(cds, yieldCurve, baseCurve, cdsCoupon);
double[] res = new double[n];
for (int i = 0; i <= index; i++) { // don't bother calculating where there is no sensitivity
double[] bumpedSpreads = makeBumpedSpreads(impSpreads, fracBumpAmount, ShiftType.ABSOLUTE, i);
IsdaCompliantCreditCurve bumpedCurve =
_curveBuilder.calibrateCreditCurve(bucketCDSs, bumpedSpreads, yieldCurve);
double price = _pricer.pv(cds, yieldCurve, bumpedCurve, cdsCoupon);
res[i] = (price - basePrice) / fracBumpAmount;
}
return res;
}
public Pricer(
CdsAnalytic cds,
IsdaCompliantYieldCurve yieldCurve,
double[] creditCurveKnots,
double fractionalSpread,
double pointsUpfront) {
_cds = cds;
_fracSpread = fractionalSpread;
_pointsUpfront = pointsUpfront;
// protection leg
_proLegIntPoints =
getIntegrationsPoints(
cds.getEffectiveProtectionStart(),
cds.getProtectionEnd(),
yieldCurve.getKnotTimes(),
creditCurveKnots);
_nProPoints = _proLegIntPoints.length;
double lgd = cds.getLGD();
_valuationDF = yieldCurve.getDiscountFactor(cds.getCashSettleTime());
_lgdDF = lgd / _valuationDF;
_proYieldCurveRT = new double[_nProPoints];
_proDF = new double[_nProPoints];
for (int i = 0; i < _nProPoints; i++) {
_proYieldCurveRT[i] = yieldCurve.getRT(_proLegIntPoints[i]);
_proDF[i] = Math.exp(-_proYieldCurveRT[i]);
}
// premium leg
_nPayments = cds.getNumPayments();
_paymentDF = new double[_nPayments];
for (int i = 0; i < _nPayments; i++) {
_paymentDF[i] = yieldCurve.getDiscountFactor(cds.getCoupon(i).getPaymentTime());
}
if (cds.isPayAccOnDefault()) {
double tmp =
cds.getNumPayments() == 1 ? cds.getEffectiveProtectionStart() : cds.getAccStart();
double[] integrationSchedule =
getIntegrationsPoints(
tmp, cds.getProtectionEnd(), yieldCurve.getKnotTimes(), creditCurveKnots);
_accRate = new double[_nPayments];
_offsetAccStart = new double[_nPayments];
_premLegIntPoints = new double[_nPayments][];
_premDF = new double[_nPayments][];
_rt = new double[_nPayments][];
_premDt = new double[_nPayments][];
for (int i = 0; i < _nPayments; i++) {
CdsCoupon c = cds.getCoupon(i);
_offsetAccStart[i] = c.getEffStart();
double offsetAccEnd = c.getEffEnd();
_accRate[i] = c.getYFRatio();
double start = Math.max(_offsetAccStart[i], cds.getEffectiveProtectionStart());
if (start >= offsetAccEnd) {
continue;
}
_premLegIntPoints[i] = truncateSetInclusive(start, offsetAccEnd, integrationSchedule);
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.getRT(_premLegIntPoints[i][k]);
_premDF[i][k] = Math.exp(-_rt[i][k]);
}
_premDt[i] = new double[n - 1];
for (int k = 1; k < n; k++) {
double dt = _premLegIntPoints[i][k] - _premLegIntPoints[i][k - 1];
_premDt[i][k - 1] = dt;
}
}
} else {
_accRate = null;
_offsetAccStart = null;
_premDF = null;
_premDt = null;
_rt = null;
_premLegIntPoints = null;
}
}
