public override void calculate()
{
Utils.QL_REQUIRE(process_.x0() > 0.0, () => "negative or null underlying given");
StrikedTypePayoff payoff = arguments_.payoff as StrikedTypePayoff;
Utils.QL_REQUIRE(payoff != null, () => "non-striked payoff given");
Exercise exercise = arguments_.exercise;
double t = process_.riskFreeRate().link.dayCounter().yearFraction(process_.riskFreeRate().link.referenceDate(),
exercise.lastDate());
double a = model_.link.parameters()[0];
double sigma = model_.link.parameters()[1];
double eta = process_.blackVolatility().link.blackVol(exercise.lastDate(), payoff.strike());
double varianceOffset;
if (a * t > Math.Pow(Const.QL_EPSILON, 0.25))
{
double v = sigma * sigma / (a * a) * (t + 2 / a * Math.Exp(-a * t) - 1 / (2 * a) * Math.Exp(-2 * a * t) - 3 / (2 * a));
double mu = 2 * rho_ * sigma * eta / a * (t - 1 / a * (1 - Math.Exp(-a * t)));
varianceOffset = v + mu;
}
else
{
// low-a algebraic limit
double v = sigma * sigma * t * t * t * (1 / 3.0 - 0.25 * a * t + 7 / 60.0 * a * a * t * t);
double mu = rho_ * sigma * eta * t * t * (1 - a * t / 3.0 + a * a * t * t / 12.0);
varianceOffset = v + mu;
}
Handle <BlackVolTermStructure> volTS = new Handle <BlackVolTermStructure>(
new ShiftedBlackVolTermStructure(varianceOffset, process_.blackVolatility()));
GeneralizedBlackScholesProcess adjProcess =
new GeneralizedBlackScholesProcess(process_.stateVariable(),
process_.dividendYield(),
process_.riskFreeRate(),
volTS);
AnalyticEuropeanEngine bsmEngine = new AnalyticEuropeanEngine(adjProcess);
VanillaOption option = new VanillaOption(payoff, exercise);
option.setupArguments(bsmEngine.getArguments());
bsmEngine.calculate();
results_ = bsmEngine.getResults() as OneAssetOption.Results;
}
public void REPORT_FAILURE(string greekName, Average.Type averageType,
double runningAccumulator, int pastFixings,
List<Date> fixingDates, StrikedTypePayoff payoff,
Exercise exercise, double s, double q, double r,
Date today, double v, double expected,
double calculated, double tolerance)
{
Assert.Fail(exercise + " "
+ exercise
+ " Asian option with "
+ averageType + " and "
+ payoff + " payoff:\n"
+ " running variable: "
+ runningAccumulator + "\n"
+ " past fixings: "
+ pastFixings + "\n"
+ " future fixings: " + fixingDates.Count() + "\n"
+ " underlying value: " + s + "\n"
+ " strike: " + payoff.strike() + "\n"
+ " dividend yield: " + q + "\n"
+ " risk-free rate: " + r + "\n"
+ " reference date: " + today + "\n"
+ " maturity: " + exercise.lastDate() + "\n"
+ " volatility: " + v + "\n\n"
+ " expected " + greekName + ": " + expected + "\n"
+ " calculated " + greekName + ": " + calculated + "\n"
+ " error: " + Math.Abs(expected - calculated)
+ "\n"
+ " tolerance: " + tolerance);
}
protected override PathPricer <IPath> pathPricer()
{
Exercise exercise = arguments_.exercise;
Utils.QL_REQUIRE(exercise.type() == Exercise.Type.European, () => "only european exercise is supported");
double exerciseTime = process_.time(exercise.lastDate());
return(new HestonHullWhitePathPricer(exerciseTime, this.arguments_.payoff, (HybridHestonHullWhiteProcess)process_));
}
protected override PathPricer <IPath> controlPathPricer()
{
HybridHestonHullWhiteProcess process = process_ as HybridHestonHullWhiteProcess;
Utils.QL_REQUIRE(process != null, () => "invalid process");
HestonProcess hestonProcess = process.hestonProcess();
Utils.QL_REQUIRE(hestonProcess != null, () =>
"first constituent of the joint stochastic process need to be of type HestonProcess");
Exercise exercise = this.arguments_.exercise;
Utils.QL_REQUIRE(exercise.type() == Exercise.Type.European, () => "only european exercise is supported");
double exerciseTime = process.time(exercise.lastDate());
return(new HestonHullWhitePathPricer(exerciseTime, this.arguments_.payoff, process));
}
void REPORT_FAILURE(string greekName, StrikedTypePayoff payoff, Exercise exercise, double s, double q, double r,
Date today, double v, double expected, double calculated, double error, double tolerance)
{
Assert.Fail(exercise + " "
+ payoff.optionType() + " option with "
+ payoff + " payoff:\n"
+ " spot value: " + s + "\n"
+ " strike: " + payoff.strike() + "\n"
+ " dividend yield: " + q + "\n"
+ " risk-free rate: " + r + "\n"
+ " reference date: " + today + "\n"
+ " maturity: " + exercise.lastDate() + "\n"
+ " volatility: " + v + "\n\n"
+ " expected " + greekName + ": " + expected + "\n"
+ " calculated " + greekName + ": " + calculated + "\n"
+ " error: " + error + "\n"
+ " tolerance: " + tolerance);
}
