AbstractSingleSwapRateProduct.java
package net.finmath.singleswaprate.products;
import java.util.function.DoubleUnaryOperator;
import net.finmath.functions.AnalyticFormulas;
import net.finmath.integration.RealIntegral;
import net.finmath.integration.SimpsonRealIntegrator;
import net.finmath.marketdata.model.curves.ForwardCurve;
import net.finmath.marketdata.model.curves.ForwardCurveFromDiscountCurve;
import net.finmath.marketdata.model.volatilities.VolatilitySurface;
import net.finmath.marketdata.model.volatilities.VolatilitySurface.QuotingConvention;
import net.finmath.marketdata.products.Swap;
import net.finmath.singleswaprate.annuitymapping.AnnuityMapping;
import net.finmath.singleswaprate.model.VolatilityCubeModel;
import net.finmath.time.Schedule;
/**
* An abstract class providing valuation methods for single swap rate products.
* Extending classes may use the valuation via replication of this class by implementing the methods:
* <ul>
* <li>payoffFunction</li>
* <li>hedgeWeight</li>
* <li>singularAddon</li>
* <li>buildAnnuityMapping</li>
* </ul>
*
* @author Christian Fries
* @author Roland Bachl
*
*/
public abstract class AbstractSingleSwapRateProduct extends AbstractAnalyticVolatilityCubeProduct {
private final Schedule fixSchedule;
private final Schedule floatSchedule;
private final String discountCurveName;
private final String forwardCurveName;
private final String volatilityCubeName;
private final QuotingConvention quotingConvention = VolatilitySurface.QuotingConvention.VOLATILITYNORMAL;
private double lowerBound = -0.15;
private double upperBound = 0.15;
private int numberOfEvaluationPoints = 500;
/**
* Create the single swap rate product.
*
* @param fixSchedule The fix schedule of the swap.
* @param floatSchedule The float schedule of the swap.
* @param discountCurveName The name of the discount curve.
* @param forwardCurveName The name of the forward curve.
* @param volatilityCubeName The name of the volatility cube.
*/
public AbstractSingleSwapRateProduct(final Schedule fixSchedule, final Schedule floatSchedule, final String discountCurveName, final String forwardCurveName,
final String volatilityCubeName) {
super();
this.fixSchedule = fixSchedule;
this.floatSchedule = floatSchedule;
this.discountCurveName = discountCurveName;
this.forwardCurveName = forwardCurveName;
this.volatilityCubeName = volatilityCubeName;
}
/**
* Set the parameters for replication.
*
* @param lowerBound The lowest strike the replication may use.
* @param upperBound The largest strike the replication may use.
* @param numberOfEvaluationPoints The number of points the replication may evaluate.
*/
public void setIntegrationParameters(final double lowerBound, final double upperBound, final int numberOfEvaluationPoints) {
this.lowerBound = lowerBound;
this.upperBound = upperBound;
this.numberOfEvaluationPoints = numberOfEvaluationPoints;
}
/**
* @return The lowest strike the replication may use.
*/
public double getIntegrationLowerBound() {
return lowerBound;
}
/**
* @return The largest strike the replication may use.
*/
public double getIntegrationUpperBound() {
return upperBound;
}
/**
* @return The number of points the replication may evaluate.
*/
public int getIntegrationNumberOfEvaluationPoints() {
return numberOfEvaluationPoints;
}
//can be overridden for better performance
@Override
public double getValue(final double evaluationTime, final VolatilityCubeModel model) {
return getValue(evaluationTime, null, model);
}
// allows to provide annuity mapping to optimize code
/**
* Return the valuation of the product using the given model.
* The model has to implement the modes of {@link VolatilityCubeModel}.
* This method allows to specify an annuity mapping to be used during the evaluation.
* This may be done to safe time, when many evaluations at different time, or of products with the same underlying swap rate, have to be done at once.
* Otherwise each call of <code>getValue</code> will first instantiate an individual annuity mapping. Which may take long for more elaborate implementations.
*
* @param evaluationTime The evaluation time as double. Cash flows prior and including this time are not considered.
* @param annuityMapping The annuity mapping to be used during valuation. If left null a new mapping will be generated.
* @param model The model under which the product is valued.
* @return The value of the product using the given model.
*/
public double getValue(final double evaluationTime, final AnnuityMapping annuityMapping, final VolatilityCubeModel model) {
if(evaluationTime > getFixSchedule().getPeriodStart(0)) {
throw new IllegalArgumentException("This framework is not set up to evaluate the product "
+this.getClass()+" at a time larger than the start of the first period ("+getFixSchedule().getPeriodStart(0)+"). Requested time was "+evaluationTime);
}
double forwardSwapRate;
ForwardCurve forwardCurve;
if(getForwardCurveName() == null) {
forwardCurve = new ForwardCurveFromDiscountCurve("From"+getDiscountCurveName(), getDiscountCurveName(), getFixSchedule().getReferenceDate(), "6M");
} else {
forwardCurve = model.getForwardCurve(getForwardCurveName());
}
forwardSwapRate = Swap.getForwardSwapRate(getFixSchedule(), getFloatSchedule(), forwardCurve, model);
// check if there is an annuity mapping provided, otherwise get new one.
final AnnuityMapping internalAnnuityMapping = annuityMapping == null ? buildAnnuityMapping(model) : annuityMapping;
double receiverLeg = 0.0;
double payerLeg = 0.0;
// check whether cube supports given lower bound
final double lowerBound = getVolatilityCubeName() == null ? this.lowerBound :
Math.max(this.lowerBound, model.getVolatilityCube(getVolatilityCubeName()).getLowestStrike(model));
// Numerical integration
final RealIntegral receiverIntegral = new SimpsonRealIntegrator(lowerBound, forwardSwapRate, numberOfEvaluationPoints);
final RealIntegral payerIntegral = new SimpsonRealIntegrator(forwardSwapRate, upperBound, numberOfEvaluationPoints);
final DoubleUnaryOperator receiverIntegrand = x -> (hedgeWeight(x, internalAnnuityMapping, model) * valuePut(x,model, forwardSwapRate));
final DoubleUnaryOperator payerIntegrand = x -> (hedgeWeight(x, internalAnnuityMapping, model) * valueCall(x,model, forwardSwapRate));
receiverLeg = receiverIntegral.integrate(receiverIntegrand);
payerLeg = payerIntegral.integrate(payerIntegrand);
double value = ((payoffFunction(forwardSwapRate, internalAnnuityMapping, model)) + receiverLeg + payerLeg
+ singularAddon(forwardSwapRate, internalAnnuityMapping, model));
if(evaluationTime != getFixSchedule().getPeriodStart(0)) {
value *= model.getDiscountCurve(getDiscountCurveName()).getDiscountFactor(model, getFixSchedule().getPeriodStart(0))
/ model.getDiscountCurve(getDiscountCurveName()).getDiscountFactor(model, evaluationTime);
}
return value;
}
//to be implemented by individual products
/**
* Payoff function of the product. Dependent only on the swap rate.
*
* @param swapRate The swap rate.
* @param annuityMapping The annuity mapping to use.
* @param model The model for context.
* @return The payoff of the product.
*/
protected abstract double payoffFunction(double swapRate, AnnuityMapping annuityMapping, VolatilityCubeModel model);
/**
* Essentially the second derivative of the payoff function.
* The hedgeweight determines the weight of the puts and calls under the integral when replicating.
*
* @param swapRate The swap rate.
* @param annuityMapping The annuity mapping to use.
* @param model The model for context.
* @return The weight during replication.
*/
protected abstract double hedgeWeight(double swapRate, AnnuityMapping annuityMapping, VolatilityCubeModel model);
/**
* As some products have a portion of their weight in a singular point,
* this is portion is split off from the <code>hedgeweight</code> and added after the integration.
*
* @param swapRate The swap rate.
* @param annuityMapping The annuity mapping to use.
* @param model The model for context.
* @return The singular addon.
*/
protected abstract double singularAddon(double swapRate, AnnuityMapping annuityMapping, VolatilityCubeModel model);
/**
* Since most annuity mappings require data from models to be created, but models are only provided at execution of <code>getValue</code>,
* the product needs to dynamically be able to build its annuity mapping.
* This method may be left to return <code>null</code>, if the product requires no annuity mapping or is intended to always receive an annuity mapping for evaluation.
*
* @param model The model for context.
* @return The annuity mapping.
*/
protected abstract AnnuityMapping buildAnnuityMapping(VolatilityCubeModel model);
//for internal use in the integration
/**
* Value of a put option on the swap rate.
*
* @param optionStrike The strike of the option.
* @param model The model for context.
* @param swapRate The swap rate.
* @return The value of a put.
*/
protected double valuePut(final double optionStrike, final VolatilityCubeModel model, final double swapRate){
return valueCall(optionStrike, model, swapRate) - (swapRate-optionStrike);
}
/**
* Value of a call option on the swap rate.
*
* @param optionStrike The strike of the option.
* @param model The model for context.
* @param swapRate The swap rate.
* @return The value of a call.
*/
protected double valueCall(final double optionStrike, final VolatilityCubeModel model, final double swapRate){
final double optionMaturity = getFixSchedule().getFixing(0);
final double termination = getFixSchedule().getPayment(getFixSchedule().getNumberOfPeriods()-1);
final double volatility = model.getVolatilityCube(getVolatilityCubeName()).getValue(model, termination, optionMaturity, optionStrike, quotingConvention);
final double value = AnalyticFormulas.bachelierOptionValue(swapRate, volatility, optionMaturity, optionStrike, 1.0);
return value;
}
/**
* @return the fixSchedule
*/
public Schedule getFixSchedule() {
return fixSchedule;
}
/**
* @return the floatSchedule
*/
public Schedule getFloatSchedule() {
return floatSchedule;
}
/**
* @return the discountCurveName
*/
public String getDiscountCurveName() {
return discountCurveName;
}
/**
* @return the forwardCurveName
*/
public String getForwardCurveName() {
return forwardCurveName;
}
/**
* @return the volatilityCubeName
*/
public String getVolatilityCubeName() {
return volatilityCubeName;
}
}