bool Var2Par(void)
{ bool ok = true;
using CppAD::AD;
using CppAD::Value;
using CppAD::Var2Par;
// domain space vector
size_t n = 2;
CPPAD_TEST_VECTOR< AD<double> > x(n);
x[0] = 3.;
x[1] = 4.;
// declare independent variables and start tape recording
CppAD::Independent(x);
// range space vector
size_t m = 1;
CPPAD_TEST_VECTOR< AD<double> > y(m);
y[0] = - x[1] * Var2Par(x[0]); // same as y[0] = -x[1] * 3.;
// cannot call Value(x[j]) or Value(y[0]) here (currently variables)
ok &= ( Value( Var2Par(x[0]) ) == 3. );
ok &= ( Value( Var2Par(x[1]) ) == 4. );
ok &= ( Value( Var2Par(y[0]) ) == -12. );
// create f: x -> y and stop tape recording
CppAD::ADFun<double> f(x, y);
// can call Value(x[j]) or Value(y[0]) here (currently parameters)
ok &= (Value(x[0]) == 3.);
ok &= (Value(x[1]) == 4.);
ok &= (Value(y[0]) == -12.);
// evaluate derivative of y w.r.t x
CPPAD_TEST_VECTOR<double> w(m);
CPPAD_TEST_VECTOR<double> dw(n);
w[0] = 1.;
dw = f.Reverse(1, w);
ok &= (dw[0] == 0.); // derivative of y[0] w.r.t x[0] is zero
ok &= (dw[1] == -3.); // derivative of y[0] w.r.t x[1] is 3
return ok;
}
bool Value(void)
{ bool ok = true;
using CppAD::AD;
using CppAD::Value;
// domain space vector
size_t n = 2;
CPPAD_TESTVECTOR(AD<double>) x(n);
x[0] = 3.;
x[1] = 4.;
// check value before recording
ok &= (Value(x[0]) == 3.);
ok &= (Value(x[1]) == 4.);
// declare independent variables and start tape recording
CppAD::Independent(x);
// range space vector
size_t m = 1;
CPPAD_TESTVECTOR(AD<double>) y(m);
y[0] = - x[1];
// cannot call Value(x[j]) or Value(y[0]) here (currently variables)
AD<double> p = 5.; // p is a parameter (does not depend on x)
ok &= (Value(p) == 5.);
// create f: x -> y and stop tape recording
CppAD::ADFun<double> f(x, y);
// can call Value(x[j]) or Value(y[0]) here (currently parameters)
ok &= (Value(x[0]) == 3.);
ok &= (Value(x[1]) == 4.);
ok &= (Value(y[0]) == -4.);
return ok;
}
