gjrgarchprocess.hpp

/* -*- mode: c++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
 
/*
 Copyright (C) 2008 Yee Man Chan
 
 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_gjrgarch_process_hpp
#define quantlib_gjrgarch_process_hpp
 
#include <ql/stochasticprocess.hpp>
#include <ql/termstructures/yieldtermstructure.hpp>
#include <ql/quote.hpp>
 
namespace QuantLib {
 
    // parameters supplied should be daily constants
    // they are annualized by setting the parameter daysPerYear
    class GJRGARCHProcess : public StochasticProcess {
      public:
        enum Discretization { PartialTruncation, FullTruncation,
                              Reflection};
 
        GJRGARCHProcess(Handle<YieldTermStructure> riskFreeRate,
                        Handle<YieldTermStructure> dividendYield,
                        Handle<Quote> s0,
                        Real v0,
                        Real omega,
                        Real alpha,
                        Real beta,
                        Real gamma,
                        Real lambda,
                        Real daysPerYear = 252.0,
                        Discretization d = FullTruncation);
 
        Size size() const override;
        Array initialValues() const override;
        Array drift(Time t, const Array& x) const override;
        Matrix diffusion(Time t, const Array& x) const override;
        Array apply(const Array& x0, const Array& dx) const override;
        Array evolve(Time t0, const Array& x0, Time dt, const Array& dw) const override;
 
        Real v0()     const { return v0_; }
        Real lambda() const { return lambda_; }
        Real omega()  const { return omega_; }
        Real alpha()  const { return alpha_; }
        Real beta()   const { return beta_; }
        Real gamma()  const { return gamma_; }
        Real daysPerYear()  const { return daysPerYear_; }
 
        const Handle<Quote>& s0() const;
        const Handle<YieldTermStructure>& dividendYield() const;
        const Handle<YieldTermStructure>& riskFreeRate() const;
 
        Time time(const Date&) const override;
 
      private:
        Handle<YieldTermStructure> riskFreeRate_, dividendYield_;
        Handle<Quote> s0_;
        Real v0_, omega_, alpha_, beta_, gamma_, lambda_, daysPerYear_;
        Discretization discretization_;
    };
 
}
 
 
#endif