103 lines
2.8 KiB
C++
103 lines
2.8 KiB
C++
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#include "../AutomaticDifferentiation.hpp"
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#include <iostream>
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#include <iomanip>
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using std::cout;
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using std::endl;
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using std::setw;
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#define PRINT_VAR(x) std::cout << #x << "\t= " << std::setprecision(16) << (x) << std::endl
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#define PRINT_DUAL(x) std::cout << #x << "\t= " << std::fixed << std::setprecision(4) << std::setw(10) << (x).a << ", " << std::setw(10) << (x).b << std::endl
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template<typename T>
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T f(const T & x)
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{
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// return T(1.) + x + x*x + T(1.)/x + log(x);
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return 1 + x + x*x + 1/x + log(x);
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}
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template<typename T>
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T df(const T & x)
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{
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return 2*x + 1 + 1.0/x - 1/pow(x, 2);
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}
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template<typename T>
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T ddf(const T & x)
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{
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return 2 - 1/pow(x, 2) + 2/pow(x, 3);
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}
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struct fFunctor
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{
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template<typename Scalar>
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Scalar operator()(Scalar const& x) {return f(x);}
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};
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CREATE_GRAD_FUNCTION_OBJECT(f, GradF);
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CREATE_GRAD_FUNCTION_OBJECT_FUNCTOR(fFunctor, GradF_funct);
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CREATE_GRAD_FUNCTION_OBJECT_FUNCTOR(GradF_funct, Grad2F_funct);
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int main()
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{
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cout.precision(16);
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double xdbl = 1.5;
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{
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cout << "Analytical\n";
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cout << "f(x) = " << f(xdbl) << endl;
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cout << "df(x)/dx = " << df(xdbl) << endl;
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cout << "d²f(x)/dx² = " << ddf(xdbl) << endl;
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}
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// 1st derivative forward
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{
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using Fd = Dual<double>;
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Fd x = xdbl;
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x.diff(0);
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Fd y = f(x);
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cout << "\nForward\n";
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cout << "f(x) = " << y.a << endl;
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cout << "df(x)/dx = " << y.d(0) << endl;
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}
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// first derivative using the gradient functor
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{
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GradFunc gradf(f<Dual<double>>, xdbl);
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double fx, dfdx;
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gradf.get_f_grad(xdbl, fx, dfdx);
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cout << "\nForward using gradient function object\n";
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cout << "f(x) = " << fx << endl;
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cout << "df(x)/dx = " << dfdx << endl;
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cout << "df(x)/dx = " << gradf(xdbl) << endl;
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}
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// first derivative using the gradient functor created through the macro
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{
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// GradF<double> gradf;
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GradF gradf;
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// GradFunc gradf(f<Dual<double>>, xdbl);
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double fx, dfdx;
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gradf.get_f_grad(xdbl, fx, dfdx);
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cout << "\nForward using gradient function object created using the macro\n";
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cout << "f(x) = " << fx << endl;
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cout << "df(x)/dx = " << dfdx << endl;
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cout << "df(x)/dx = " << gradf(xdbl) << endl;
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{
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GradF_funct gradf_funct;
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Grad2F_funct grad2f_funct;
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PRINT_VAR(gradf(1.5f));
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PRINT_VAR(gradf_funct(1.5));
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// PRINT_VAR(grad2f_funct(1.5));// for this to work, the operator+-*/(A, Dual<B>) must not be defined (conflict with operator from valarray)
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// third order does not work anyway (can't convert a double to Dual<Dual<Dual<double>>>...)
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}
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}
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return 0;
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}
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