blackscholesprocess.hpp

/* -*- mode: c++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
 
/*
 Copyright (C) 2001, 2002, 2003 Sadruddin Rejeb
 Copyright (C) 2003 Ferdinando Ametrano
 Copyright (C) 2004, 2005, 2006, 2007, 2009 StatPro Italia srl
 Copyright (C) 2015 Peter Caspers
 
 This file is part of QuantLib, a free-software/open-source library
 for financial quantitative analysts and developers - http://quantlib.org/
 
 QuantLib is free software: you can redistribute it and/or modify it
 under the terms of the QuantLib license.  You should have received a
 copy of the license along with this program; if not, please email
 <quantlib-dev@lists.sf.net>. The license is also available online at
 <http://quantlib.org/license.shtml>.
 
 This program is distributed in the hope that it will be useful, but WITHOUT
 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 FOR A PARTICULAR PURPOSE.  See the license for more details.
*/
 
#ifndef quantlib_black_scholes_process_hpp
#define quantlib_black_scholes_process_hpp
 
#include <ql/stochasticprocess.hpp>
#include <ql/processes/eulerdiscretization.hpp>
#include <ql/termstructures/yieldtermstructure.hpp>
#include <ql/termstructures/volatility/equityfx/blackvoltermstructure.hpp>
#include <ql/termstructures/volatility/equityfx/localvoltermstructure.hpp>
#include <ql/quote.hpp>
 
namespace QuantLib {
 
    class LocalConstantVol;
    class LocalVolCurve;
 
 
    class GeneralizedBlackScholesProcess : public StochasticProcess1D {
      public:
        GeneralizedBlackScholesProcess(Handle<Quote> x0,
                                       Handle<YieldTermStructure> dividendTS,
                                       Handle<YieldTermStructure> riskFreeTS,
                                       Handle<BlackVolTermStructure> blackVolTS,
                                       const ext::shared_ptr<discretization>& d =
                                           ext::shared_ptr<discretization>(new EulerDiscretization),
                                       bool forceDiscretization = false);
 
        GeneralizedBlackScholesProcess(Handle<Quote> x0,
                                       Handle<YieldTermStructure> dividendTS,
                                       Handle<YieldTermStructure> riskFreeTS,
                                       Handle<BlackVolTermStructure> blackVolTS,
                                       Handle<LocalVolTermStructure> localVolTS);
 
 
        Real x0() const override;
        Real drift(Time t, Real x) const override;
        Real diffusion(Time t, Real x) const override;
        Real apply(Real x0, Real dx) const override;
        Real expectation(Time t0, Real x0, Time dt) const override;
        Real stdDeviation(Time t0, Real x0, Time dt) const override;
        Real variance(Time t0, Real x0, Time dt) const override;
        Real evolve(Time t0, Real x0, Time dt, Real dw) const override;
        Time time(const Date&) const override;
 
        void update() override;
 
        const Handle<Quote>& stateVariable() const;
        const Handle<YieldTermStructure>& dividendYield() const;
        const Handle<YieldTermStructure>& riskFreeRate() const;
        const Handle<BlackVolTermStructure>& blackVolatility() const;
        const Handle<LocalVolTermStructure>& localVolatility() const;
      private:
        Handle<Quote> x0_;
        Handle<YieldTermStructure> riskFreeRate_, dividendYield_;
        Handle<BlackVolTermStructure> blackVolatility_;
        Handle<LocalVolTermStructure> externalLocalVolTS_;
        bool forceDiscretization_;
        bool hasExternalLocalVol_;
        mutable RelinkableHandle<LocalVolTermStructure> localVolatility_;
        mutable bool updated_, isStrikeIndependent_;
    };
 
 
    class BlackScholesProcess : public GeneralizedBlackScholesProcess {
      public:
        BlackScholesProcess(
            const Handle<Quote>& x0,
            const Handle<YieldTermStructure>& riskFreeTS,
            const Handle<BlackVolTermStructure>& blackVolTS,
            const ext::shared_ptr<discretization>& d =
                  ext::shared_ptr<discretization>(new EulerDiscretization),
            bool forceDiscretization = false);
    };
 
 
    class BlackScholesMertonProcess : public GeneralizedBlackScholesProcess {
      public:
        BlackScholesMertonProcess(
            const Handle<Quote>& x0,
            const Handle<YieldTermStructure>& dividendTS,
            const Handle<YieldTermStructure>& riskFreeTS,
            const Handle<BlackVolTermStructure>& blackVolTS,
            const ext::shared_ptr<discretization>& d =
                  ext::shared_ptr<discretization>(new EulerDiscretization),
            bool forceDiscretization = false);
    };
 
 
    class BlackProcess : public GeneralizedBlackScholesProcess {
      public:
        BlackProcess(
            const Handle<Quote>& x0,
            const Handle<YieldTermStructure>& riskFreeTS,
            const Handle<BlackVolTermStructure>& blackVolTS,
            const ext::shared_ptr<discretization>& d =
                  ext::shared_ptr<discretization>(new EulerDiscretization),
            bool forceDiscretization = false);
    };
 
 
    class GarmanKohlagenProcess : public GeneralizedBlackScholesProcess {
      public:
        GarmanKohlagenProcess(
            const Handle<Quote>& x0,
            const Handle<YieldTermStructure>& foreignRiskFreeTS,
            const Handle<YieldTermStructure>& domesticRiskFreeTS,
            const Handle<BlackVolTermStructure>& blackVolTS,
            const ext::shared_ptr<discretization>& d =
                  ext::shared_ptr<discretization>(new EulerDiscretization),
            bool forceDiscretization = false);
    };
 
}
 
 
#endif