public void testCrankNicolsonWithDamping()
{
SavedSettings backup = new SavedSettings();
DayCounter dc = new Actual360();
Date today = Date.Today;
SimpleQuote spot = new SimpleQuote(100.0);
YieldTermStructure qTS = Utilities.flatRate(today, 0.06, dc);
YieldTermStructure rTS = Utilities.flatRate(today, 0.06, dc);
BlackVolTermStructure volTS = Utilities.flatVol(today, 0.35, dc);
StrikedTypePayoff payoff =
new CashOrNothingPayoff(Option.Type.Put, 100, 10.0);
double maturity = 0.75;
Date exDate = today + Convert.ToInt32(maturity * 360 + 0.5);
Exercise exercise = new EuropeanExercise(exDate);
BlackScholesMertonProcess process = new
BlackScholesMertonProcess(new Handle <Quote>(spot),
new Handle <YieldTermStructure>(qTS),
new Handle <YieldTermStructure>(rTS),
new Handle <BlackVolTermStructure>(volTS));
IPricingEngine engine =
new AnalyticEuropeanEngine(process);
VanillaOption opt = new VanillaOption(payoff, exercise);
opt.setPricingEngine(engine);
double expectedPV = opt.NPV();
double expectedGamma = opt.gamma();
// fd pricing using implicit damping steps and Crank Nicolson
int csSteps = 25, dampingSteps = 3, xGrid = 400;
List <int> dim = new InitializedList <int>(1, xGrid);
FdmLinearOpLayout layout = new FdmLinearOpLayout(dim);
Fdm1dMesher equityMesher =
new FdmBlackScholesMesher(
dim[0], process, maturity, payoff.strike(),
null, null, 0.0001, 1.5,
new Pair <double?, double?>(payoff.strike(), 0.01));
FdmMesher mesher =
new FdmMesherComposite(equityMesher);
FdmBlackScholesOp map =
new FdmBlackScholesOp(mesher, process, payoff.strike());
FdmInnerValueCalculator calculator =
new FdmLogInnerValue(payoff, mesher, 0);
object rhs = new Vector(layout.size());
Vector x = new Vector(layout.size());
FdmLinearOpIterator endIter = layout.end();
for (FdmLinearOpIterator iter = layout.begin(); iter != endIter;
++iter)
{
(rhs as Vector)[iter.index()] = calculator.avgInnerValue(iter, maturity);
x[iter.index()] = mesher.location(iter, 0);
}
FdmBackwardSolver solver = new FdmBackwardSolver(map, new FdmBoundaryConditionSet(),
new FdmStepConditionComposite(),
new FdmSchemeDesc().Douglas());
solver.rollback(ref rhs, maturity, 0.0, csSteps, dampingSteps);
MonotonicCubicNaturalSpline spline = new MonotonicCubicNaturalSpline(x, x.Count, rhs as Vector);
double s = spot.value();
double calculatedPV = spline.value(Math.Log(s));
double calculatedGamma = (spline.secondDerivative(Math.Log(s))
- spline.derivative(Math.Log(s))) / (s * s);
double relTol = 2e-3;
if (Math.Abs(calculatedPV - expectedPV) > relTol * expectedPV)
{
QAssert.Fail("Error calculating the PV of the digital option" +
"\n rel. tolerance: " + relTol +
"\n expected: " + expectedPV +
"\n calculated: " + calculatedPV);
}
if (Math.Abs(calculatedGamma - expectedGamma) > relTol * expectedGamma)
{
QAssert.Fail("Error calculating the Gamma of the digital option" +
"\n rel. tolerance: " + relTol +
"\n expected: " + expectedGamma +
"\n calculated: " + calculatedGamma);
}
}
static void Main(string[] args)
{
const int xSteps = 100;
const int tSteps = 25;
const int dampingSteps = 0;
Date today = new Date(15, Month.January, 2020);
Settings.instance().setEvaluationDate(today);
DayCounter dc = new Actual365Fixed();
YieldTermStructureHandle rTS = new YieldTermStructureHandle(
new FlatForward(today, 0.06, dc));
YieldTermStructureHandle qTS = new YieldTermStructureHandle(
new FlatForward(today, 0.02, dc));
const double strike = 110.0;
StrikedTypePayoff payoff = new PlainVanillaPayoff(Option.Type.Put, strike);
Date maturityDate = today.Add(new Period(1, TimeUnit.Years));
double maturity = dc.yearFraction(today, maturityDate);
Exercise exercise = new AmericanExercise(today, maturityDate);
Instrument vanillaOption = new VanillaOption(payoff, exercise);
QuoteHandle spot = new QuoteHandle(new SimpleQuote(100.0));
BlackVolTermStructureHandle volatility = new BlackVolTermStructureHandle(
new BlackConstantVol(today, new TARGET(), 0.20, dc));
BlackScholesMertonProcess process =
new BlackScholesMertonProcess(spot, qTS, rTS, volatility);
vanillaOption.setPricingEngine(new FdBlackScholesVanillaEngine(
process, tSteps, xSteps, dampingSteps));
double expected = vanillaOption.NPV();
// build an PDE engine from scratch
Fdm1dMesher equityMesher = new FdmBlackScholesMesher(
xSteps, process, maturity, strike,
nullDouble(), nullDouble(), 0.0001, 1.5,
new DoublePair(strike, 0.1));
FdmMesherComposite mesher = new FdmMesherComposite(equityMesher);
FdmLinearOpComposite op = new FdmBlackScholesOp(mesher, process, strike);
FdmInnerValueCalculator calc = new FdmLogInnerValue(payoff, mesher, 0);
QlArray x = new QlArray(equityMesher.size());
QlArray rhs = new QlArray(equityMesher.size());
FdmLinearOpIterator iter = mesher.layout().begin();
for (uint i = 0; i < rhs.size(); ++i, iter.increment())
{
x.set(i, mesher.location(iter, 0));
rhs.set(i, calc.avgInnerValue(iter, maturity));
}
FdmBoundaryConditionSet bcSet = new FdmBoundaryConditionSet();
FdmStepConditionComposite stepCondition =
FdmStepConditionComposite.vanillaComposite(
new DividendSchedule(), exercise, mesher, calc, today, dc);
FdmLinearOpComposite proxyOp = new FdmLinearOpCompositeProxy(
new FdmBSDelegate(op));
FdmBackwardSolver solver = new FdmBackwardSolver(
proxyOp, bcSet, stepCondition, FdmSchemeDesc.Douglas());
solver.rollback(rhs, maturity, 0.0, tSteps, dampingSteps);
double logS = Math.Log(spot.value());
double calculated = new CubicNaturalSpline(x, rhs).call(logS);
Console.WriteLine("Homebrew PDE engine : {0:0.0000}", calculated);
Console.WriteLine("FdBlackScholesVanillaEngine: {0:0.0000}", expected);
}
