$\newcommand{\W}[1]{ \; #1 \; } \newcommand{\R}[1]{ {\rm #1} } \newcommand{\B}[1]{ {\bf #1} } \newcommand{\D}[2]{ \frac{\partial #1}{\partial #2} } \newcommand{\DD}[3]{ \frac{\partial^2 #1}{\partial #2 \partial #3} } \newcommand{\Dpow}[2]{ \frac{\partial^{#1}}{\partial {#2}^{#1}} } \newcommand{\dpow}[2]{ \frac{ {\rm d}^{#1}}{{\rm d}\, {#2}^{#1}} }$
 # include <cppad/cppad.hpp> bool ParVar(void) { bool ok = true; using CppAD::AD; using CppAD::VecAD; using CppAD::Parameter; using CppAD::Variable; // declare independent variables and start tape recording size_t n = 1; CPPAD_TESTVECTOR(AD<double>) x(n); x[0] = 0.; ok &= Parameter(x[0]); // x[0] is a paraemter here CppAD::Independent(x); ok &= Variable(x[0]); // now x[0] is a variable // dependent variable vector size_t m = 2; CPPAD_TESTVECTOR(AD<double>) y(m); y[0] = 2.; ok &= Parameter(y[0]); // y[0] does not depend on x[0] y[1] = fabs(x[0]); ok &= Variable(y[1]); // y[1] does depends on x[0] // VecAD objects VecAD<double> z(2); z[0] = 0.; z[1] = 1.; ok &= Parameter(z); // z does not depend on x[0] z[x[0]] = 2.; ok &= Variable(z); // z depends on x[0] // create f: x -> y and stop tape recording CppAD::ADFun<double> f(x, y); // check that now all AD<double> objects are parameters ok &= Parameter(x[0]); ok &= ! Variable(x[0]); ok &= Parameter(y[0]); ok &= ! Variable(y[0]); ok &= Parameter(y[1]); ok &= ! Variable(y[1]); // check that the VecAD<double> object is a parameter ok &= Parameter(z); return ok; }