@Test
public void testNormal() {
final ProbabilityDistribution<Double> highDOF = new StudentTDistribution(1000000, ENGINE);
final ProbabilityDistribution<Double> normal = new NormalDistribution(0, 1, ENGINE);
final double eps = 1e-4;
double x;
for (int i = 0; i < 100; i++) {
x = RANDOM.nextDouble();
assertEquals(highDOF.getCDF(x), normal.getCDF(x), eps);
assertEquals(highDOF.getPDF(x), normal.getPDF(x), eps);
assertEquals(highDOF.getInverseCDF(x), normal.getInverseCDF(x), eps);
}
}
@Test
/** Test the present value. */
public void presentValueExplicit() {
final MultipleCurrencyAmount pv = METHOD_HW.presentValue(SWAPTION_LONG_PAYER, HW_MULTICURVES);
final double timeToExpiry = SWAPTION_LONG_PAYER.getTimeToExpiry();
final AnnuityPaymentFixed cfe =
CFEC.visitSwap(SWAPTION_LONG_PAYER.getUnderlyingSwap(), MULTICURVES);
final int numberOfPayments = cfe.getNumberOfPayments();
final double alpha[] = new double[numberOfPayments];
final double disccf[] = new double[numberOfPayments];
for (int loopcf = 0; loopcf < numberOfPayments; loopcf++) {
alpha[loopcf] =
MODEL.alpha(
HW_PARAMETERS,
0.0,
timeToExpiry,
timeToExpiry,
cfe.getNthPayment(loopcf).getPaymentTime());
disccf[loopcf] =
MULTICURVES.getDiscountFactor(EUR, cfe.getNthPayment(loopcf).getPaymentTime())
* cfe.getNthPayment(loopcf).getAmount();
}
final double kappa = MODEL.kappa(disccf, alpha);
double pvExpected = 0.0;
for (int loopcf = 0; loopcf < numberOfPayments; loopcf++) {
pvExpected += disccf[loopcf] * NORMAL.getCDF(-kappa - alpha[loopcf]);
}
assertEquals(
"Swaption physical - Hull-White - present value", pvExpected, pv.getAmount(EUR), 1E-2);
final MultipleCurrencyAmount pv2 =
METHOD_HW.presentValue(SWAPTION_LONG_PAYER, cfe, HW_MULTICURVES);
assertEquals("Swaption physical - Hull-White - present value", pv, pv2);
}
/**
* Compute theta price of cash-or-nothing option
*
* @param spot The spot
* @param strike The strike
* @param timeToExpiry The time to expiry
* @param lognormalVol The log-normal volatility
* @param interestRate The interest rate
* @param costOfCarry The cost-of-carry
* @param isCall True for calls, false for puts
* @return The option price
*/
public static double theta(
final double spot,
final double strike,
final double timeToExpiry,
final double lognormalVol,
final double interestRate,
final double costOfCarry,
final boolean isCall) {
ArgumentChecker.isTrue(spot > 0.0, "negative/NaN spot; have {}", spot);
ArgumentChecker.isTrue(strike > 0.0, "negative/NaN strike; have {}", strike);
ArgumentChecker.isTrue(timeToExpiry > 0.0, "negative/NaN timeToExpiry; have {}", timeToExpiry);
ArgumentChecker.isTrue(lognormalVol > 0.0, "negative/NaN lognormalVol; have {}", lognormalVol);
ArgumentChecker.isFalse(Double.isNaN(interestRate), "interestRate is NaN");
ArgumentChecker.isFalse(Double.isNaN(costOfCarry), "costOfCarry is NaN");
final double d =
(Math.log(spot / strike) + (costOfCarry - 0.5 * lognormalVol * lognormalVol) * timeToExpiry)
/ lognormalVol
/ Math.sqrt(timeToExpiry);
final double sign = isCall ? 1. : -1.;
final double div =
0.5
* (-Math.log(spot / strike) / Math.pow(timeToExpiry, 1.5)
+ (costOfCarry - 0.5 * lognormalVol * lognormalVol) / Math.pow(timeToExpiry, 0.5))
/ lognormalVol;
return interestRate * Math.exp(-interestRate * timeToExpiry) * NORMAL.getCDF(sign * d)
- sign * Math.exp(-interestRate * timeToExpiry) * NORMAL.getPDF(d) * div;
}
/**
* Computes the price curve sensitivity in the Hull-White one factor model.
*
* @param security The option security.
* @param hwMulticurves The multi-curves provider with Hull-White one factor parameters.
* @return The curve sensitivity.
*/
@Override
public MulticurveSensitivity priceCurveSensitivity(
final InterestRateFutureOptionMarginSecurity security,
final HullWhiteOneFactorProviderInterface hwMulticurves) {
ArgumentChecker.notNull(security, "Option security");
ArgumentChecker.notNull(hwMulticurves, "Hull-White and multi-curves data");
ArgumentChecker.isTrue(
security.getCurrency().equals(hwMulticurves.getHullWhiteCurrency()),
"Model currency incompatible with security currency");
final MulticurveProviderInterface multicurves = hwMulticurves.getMulticurveProvider();
final HullWhiteOneFactorPiecewiseConstantParameters parameters =
hwMulticurves.getHullWhiteParameters();
final double k = security.getStrike();
final double ktilde = 1.0 - k;
final double theta = security.getExpirationTime();
final double delta = security.getUnderlyingFuture().getFixingPeriodAccrualFactor();
final double t0 = security.getUnderlyingFuture().getTradingLastTime();
final double t1 = security.getUnderlyingFuture().getFixingPeriodStartTime();
final double t2 = security.getUnderlyingFuture().getFixingPeriodEndTime();
// forward sweep
final double alpha = MODEL.alpha(parameters, 0.0, theta, t1, t2);
final double gamma = MODEL.futuresConvexityFactor(parameters, t0, t1, t2);
final double forward =
multicurves.getSimplyCompoundForwardRate(
security.getUnderlyingFuture().getIborIndex(), t1, t2, delta);
final double kappa =
-Math.log((1 + delta * ktilde) / (1 + delta * forward) / gamma) / alpha - 0.5 * alpha;
// Bakcward sweep
final double priceBar = 1.0;
double forwardBar;
if (security.isCall()) {
final double normalAlphaKappa = NORMAL.getCDF(-kappa - alpha);
forwardBar = -gamma * normalAlphaKappa * priceBar;
} else {
final double normalAlphaKappa = NORMAL.getCDF(kappa + alpha);
forwardBar = gamma * normalAlphaKappa * priceBar;
}
final Map<String, List<ForwardSensitivity>> mapFwd = new HashMap<>();
final List<ForwardSensitivity> listForward = new ArrayList<>();
listForward.add(new SimplyCompoundedForwardSensitivity(t1, t2, delta, forwardBar));
mapFwd.put(
hwMulticurves
.getMulticurveProvider()
.getName(security.getUnderlyingFuture().getIborIndex()),
listForward);
return MulticurveSensitivity.ofForward(mapFwd);
}
@Test
public void test() {
ProbabilityDistribution<Double> dist = new StudentTDistribution(1, ENGINE);
assertCDFWithNull(dist);
assertPDFWithNull(dist);
assertInverseCDF(X, dist);
for (int i = 0; i < 10; i++) {
dist = new StudentTDistribution(DOF[i], ENGINE);
assertEquals(P[i], dist.getCDF(X[i]), EPS);
}
}
/**
* Computes the price in the Hull-White one factor model.
*
* @param security The option security.
* @param hwMulticurves The multi-curves provider with Hull-White one factor parameters.
* @return The price.
*/
@Override
public double price(
final InterestRateFutureOptionMarginSecurity security,
final HullWhiteOneFactorProviderInterface hwMulticurves) {
ArgumentChecker.notNull(security, "Option security");
ArgumentChecker.notNull(hwMulticurves, "Hull-White and multi-curves data");
ArgumentChecker.isTrue(
security.getCurrency().equals(hwMulticurves.getHullWhiteCurrency()),
"Model currency incompatible with security currency");
final MulticurveProviderInterface multicurves = hwMulticurves.getMulticurveProvider();
final HullWhiteOneFactorPiecewiseConstantParameters parameters =
hwMulticurves.getHullWhiteParameters();
final double k = security.getStrike();
final double ktilde = 1.0 - k;
final double theta = security.getExpirationTime();
final double delta = security.getUnderlyingFuture().getFixingPeriodAccrualFactor();
final double t0 = security.getUnderlyingFuture().getTradingLastTime();
final double t1 = security.getUnderlyingFuture().getFixingPeriodStartTime();
final double t2 = security.getUnderlyingFuture().getFixingPeriodEndTime();
final double alpha = MODEL.alpha(parameters, 0.0, theta, t1, t2);
final double gamma = MODEL.futuresConvexityFactor(parameters, t0, t1, t2);
final double forward =
multicurves.getSimplyCompoundForwardRate(
security.getUnderlyingFuture().getIborIndex(), t1, t2, delta);
final double kappa =
-Math.log((1 + delta * ktilde) / (1 + delta * forward) / gamma) / alpha - 0.5 * alpha;
if (security.isCall()) {
final double normalKappa = NORMAL.getCDF(-kappa);
final double normalAlphaKappa = NORMAL.getCDF(-kappa - alpha);
return (1 - k + 1.0 / delta) * normalKappa
- (1.0 / delta + forward) * gamma * normalAlphaKappa;
}
final double normalKappa = NORMAL.getCDF(kappa);
final double normalAlphaKappa = NORMAL.getCDF(kappa + alpha);
return (1.0 / delta + forward) * gamma * normalAlphaKappa - (1 - k + 1.0 / delta) * normalKappa;
}