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AD Absolute Zero Multiplication: Example and Test
 # include <cppad/cppad.hpp> # include <cmath> bool azmul(void) { bool ok = true; using CppAD::AD; using CppAD::NearEqual; double inf = std::numeric_limits<double>::infinity(); double eps = 10. * std::numeric_limits<double>::epsilon(); // domain space vector size_t n = 2; double x = 0.5; double y = 2.0; CPPAD_TESTVECTOR(AD<double>) axy(n); axy[0] = x; axy[1] = y; // declare independent variables and start tape recording CppAD::Independent(axy); // range space vector size_t m = 5; CPPAD_TESTVECTOR(AD<double>) az(m); az[0] = CppAD::azmul(axy[0], axy[1]); // azmul(variable, variable) az[1] = CppAD::azmul(axy[0], inf); // azmul(variable, parameter=inf) az[2] = CppAD::azmul(axy[0], 3.0); // azmul(variable, parameter=3.0) az[3] = CppAD::azmul(0.0, axy[1]); // azmul(parameter=0.0, variable) az[4] = CppAD::azmul(4.0, axy[1]); // azmul(parameter=4.0, variable) // create f: axy -> az and stop tape recording CppAD::ADFun<double> f(axy, az); // check value when x is not zero ok &= NearEqual(az[0] , x * y, eps, eps); ok &= az[1] == inf; ok &= NearEqual(az[2] , x * 3.0, eps, eps); ok &= az[3] == 0.0; ok &= NearEqual(az[4] , 4.0 * y, eps, eps); // check value x is zero and y is infinity CPPAD_TESTVECTOR(double) xy(n), z(m); xy[0] = 0.0; xy[1] = inf; z = f.Forward(0, xy); ok &= z[0] == 0.0; ok &= z[1] == 0.0; ok &= z[2] == 0.0; ok &= z[3] == 0.0; ok &= z[4] == inf; return ok; } 
Input File: example/general/azmul.cpp