/** Test getDelta, getGamma and getVega */
@Test
public void greeksTest() {
double tol = 1.0e-12;
double eps = 1.0e-5;
double[] priceDerivative = new double[3];
for (EuropeanVanillaOption option :
new EuropeanVanillaOption[] {ITM_CALL, ITM_PUT, OTM_CALL, OTM_PUT, ATM_CALL, ATM_PUT}) {
// consistency with getPriceFunction for first order derivatives
FUNCTION.getPriceAdjoint(option, VOL_DATA, priceDerivative);
double delta = FUNCTION.getDelta(option, VOL_DATA);
double vega = FUNCTION.getVega(option, VOL_DATA);
assertEquals(delta, priceDerivative[0], tol);
assertEquals(vega, priceDerivative[1], tol);
// testing second order derivative against finite difference approximation
NormalFunctionData dataUp = new NormalFunctionData(F + eps, DF, SIGMA);
NormalFunctionData dataDw = new NormalFunctionData(F - eps, DF, SIGMA);
double deltaUp = FUNCTION.getDelta(option, dataUp);
double deltaDw = FUNCTION.getDelta(option, dataDw);
double ref = 0.5 * (deltaUp - deltaDw) / eps;
double gamma = FUNCTION.getGamma(option, VOL_DATA);
assertEquals(ref, gamma, eps);
EuropeanVanillaOption optionUp =
new EuropeanVanillaOption(option.getStrike(), T + eps, option.isCall());
EuropeanVanillaOption optionDw =
new EuropeanVanillaOption(option.getStrike(), T - eps, option.isCall());
double priceTimeUp = FUNCTION.getPriceAdjoint(optionUp, VOL_DATA, priceDerivative);
double priceTimeDw = FUNCTION.getPriceAdjoint(optionDw, VOL_DATA, priceDerivative);
ref = -0.5 * (priceTimeUp - priceTimeDw) / eps;
double theta = FUNCTION.getTheta(option, VOL_DATA);
assertEquals(ref, theta, eps);
}
}
/** Testing the branch for sigmaRootT < 1e-16 */
@Test
public void smallParameterGreeksTest() {
double eps = 1.0e-5;
double[] der = new double[3];
NormalFunctionData dataVolUp = new NormalFunctionData(F, DF, eps);
NormalFunctionData dataFwUp = new NormalFunctionData(F + eps, DF, 0.0);
NormalFunctionData dataFwDw = new NormalFunctionData(F - eps, DF, 0.0);
for (EuropeanVanillaOption option :
new EuropeanVanillaOption[] {ITM_CALL, ITM_PUT, OTM_CALL, OTM_PUT, ATM_CALL, ATM_PUT}) {
double delta = FUNCTION.getDelta(option, ZERO_VOL_DATA);
double priceUp = FUNCTION.getPriceAdjoint(option, dataFwUp, der);
double priceDw = FUNCTION.getPriceAdjoint(option, dataFwDw, der);
double refDelta = 0.5 * (priceUp - priceDw) / eps;
assertEquals(refDelta, delta, eps);
double vega = FUNCTION.getVega(option, ZERO_VOL_DATA);
double priceVolUp = FUNCTION.getPriceAdjoint(option, dataVolUp, der);
double price = FUNCTION.getPriceAdjoint(option, ZERO_VOL_DATA, der);
double refVega = (priceVolUp - price) / eps;
assertEquals(refVega, vega, eps);
double gamma = FUNCTION.getGamma(option, ZERO_VOL_DATA);
double deltaUp = FUNCTION.getDelta(option, dataFwUp);
double deltaDw = FUNCTION.getDelta(option, dataFwDw);
double refGamma = 0.5 * (deltaUp - deltaDw) / eps;
if (Math.abs(refGamma) > 0.1 / eps) { // infinity handled
assertTrue(Double.isInfinite(gamma));
} else {
assertEquals(refGamma, gamma, eps);
}
EuropeanVanillaOption optionUp =
new EuropeanVanillaOption(option.getStrike(), T + eps, option.isCall());
EuropeanVanillaOption optionDw =
new EuropeanVanillaOption(option.getStrike(), T - eps, option.isCall());
double priceTimeUp = FUNCTION.getPriceAdjoint(optionUp, ZERO_VOL_DATA, der);
double priceTimeDw = FUNCTION.getPriceAdjoint(optionDw, ZERO_VOL_DATA, der);
double refTheta = -0.5 * (priceTimeUp - priceTimeDw) / eps;
double theta = FUNCTION.getTheta(option, ZERO_VOL_DATA);
assertEquals(refTheta, theta, eps);
}
}