/usr/include/ql/experimental/barrieroption/vannavolgainterpolation.hpp is in libquantlib0-dev 1.7.1-1.
This file is owned by root:root, with mode 0o644.
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/*
Copyright (C) 2013 Yue Tian
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.
*/
/*! \file vannavolgainterpolation.hpp
\brief Vanna/Volga interpolation between discrete points
*/
#ifndef quantlib_vanna_volga_interpolation_hpp
#define quantlib_vanna_volga_interpolation_hpp
#include <ql/math/interpolation.hpp>
#include <ql/pricingengines/blackformula.hpp>
#include <ql/math/distributions/normaldistribution.hpp>
#include <boost/make_shared.hpp>
#include <vector>
namespace QuantLib {
namespace detail {
template<class I1, class I2> class VannaVolgaInterpolationImpl;
}
//! %Vanna Volga interpolation between discrete points
class VannaVolgaInterpolation : public Interpolation {
public:
/*! \pre the \f$ x \f$ values must be sorted. */
template <class I1, class I2>
VannaVolgaInterpolation(const I1& xBegin, const I1& xEnd,
const I2& yBegin,
Real spot,
DiscountFactor dDiscount,
DiscountFactor fDiscount,
Time T) {
impl_ = boost::make_shared<
detail::VannaVolgaInterpolationImpl<I1,I2> >(
xBegin, xEnd, yBegin,
spot, dDiscount, fDiscount, T);
impl_->update();
}
};
//! %VannaVolga-interpolation factory and traits
class VannaVolga {
public:
VannaVolga(Real spot,
DiscountFactor dDiscount,
DiscountFactor fDiscount,
Time T)
:spot_(spot), dDiscount_(dDiscount), fDiscount_(fDiscount), T_(T)
{}
template <class I1, class I2>
Interpolation interpolate(const I1& xBegin, const I1& xEnd,
const I2& yBegin) const {
return VannaVolgaInterpolation(xBegin, xEnd, yBegin, spot_, dDiscount_, fDiscount_, T_);
}
static const Size requiredPoints = 3;
private:
Real spot_;
DiscountFactor dDiscount_;
DiscountFactor fDiscount_;
Time T_;
};
namespace detail {
template <class I1, class I2>
class VannaVolgaInterpolationImpl
: public Interpolation::templateImpl<I1,I2> {
public:
VannaVolgaInterpolationImpl(const I1& xBegin, const I1& xEnd,
const I2& yBegin,
Real spot,
DiscountFactor dDiscount,
DiscountFactor fDiscount,
Time T)
: Interpolation::templateImpl<I1,I2>(xBegin, xEnd, yBegin,
VannaVolga::requiredPoints),
spot_(spot), dDiscount_(dDiscount), fDiscount_(fDiscount), T_(T) {
QL_REQUIRE(this->xEnd_-this->xBegin_ == 3,
"Vanna Volga Interpolator only interpolates 3 volatilities in strike space");
}
void update() {
//atmVol should be the second vol
atmVol_ = this->yBegin_[1];
fwd_ = spot_*fDiscount_/dDiscount_;
for(Size i = 0; i < 3; i++){
premiaBS.push_back(blackFormula(Option::Call, this->xBegin_[i], fwd_, atmVol_ * std::sqrt(T_), dDiscount_));
premiaMKT.push_back(blackFormula(Option::Call, this->xBegin_[i], fwd_, this->yBegin_[i] * std::sqrt(T_), dDiscount_));
vegas.push_back(vega(this->xBegin_[i]));
}
}
Real value(Real k) const {
Real x1 = vega(k)/vegas[0]
* (std::log(this->xBegin_[1]/k) * std::log(this->xBegin_[2]/k))
/ (std::log(this->xBegin_[1]/this->xBegin_[0]) * std::log(this->xBegin_[2]/this->xBegin_[0]));
Real x2 = vega(k)/vegas[1]
* (std::log(k/this->xBegin_[0]) * std::log(this->xBegin_[2]/k))
/ (std::log(this->xBegin_[1]/this->xBegin_[0]) * std::log(this->xBegin_[2]/this->xBegin_[1]));
Real x3 = vega(k)/vegas[2]
* (std::log(k/this->xBegin_[0]) * std::log(k/this->xBegin_[1]))
/ (std::log(this->xBegin_[2]/this->xBegin_[0]) * std::log(this->xBegin_[2]/this->xBegin_[1]));
Real cBS = blackFormula(Option::Call, k, fwd_, atmVol_ * std::sqrt(T_), dDiscount_);
Real c = cBS + x1*(premiaMKT[0] - premiaBS[0]) + x2*(premiaMKT[1] - premiaBS[1]) + x3*(premiaMKT[2] - premiaBS[2]);
Real std = blackFormulaImpliedStdDev(Option::Call, k, fwd_, c, dDiscount_);
return std / sqrt(T_);
}
Real primitive(Real) const {
QL_FAIL("Vanna Volga primitive not implemented");
}
Real derivative(Real) const {
QL_FAIL("Vanna Volga derivative not implemented");
}
Real secondDerivative(Real) const {
QL_FAIL("Vanna Volga secondDerivative not implemented");
}
private:
std::vector<Real> premiaBS;
std::vector<Real> premiaMKT;
std::vector<Real> vegas;
Real atmVol_;
Real spot_;
Real fwd_;
DiscountFactor dDiscount_;
DiscountFactor fDiscount_;
Time T_;
Real vega(Real k) const {
Real d1 = (std::log(fwd_/k) + 0.5 * std::pow(atmVol_, 2.0) * T_)/(atmVol_ * std::sqrt(T_));
NormalDistribution norm;
return spot_ * dDiscount_ * std::sqrt(T_) * norm(d1);
}
};
}
}
#endif
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