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# include <cppad/vector.hpp>
# include <cppad/poly.hpp>
# include <cppad/speed/uniform_01.hpp>
# include <FADBAD++/tadiff.h>
bool compute_poly(
size_t size ,
size_t repeat ,
CppAD::vector<double> &a , // coefficients of polynomial
CppAD::vector<double> &z , // polynomial argument value
CppAD::vector<double> &ddp ) // second derivative w.r.t z
{
// -----------------------------------------------------
// setup
size_t i; // temporary index
T<double> Z; // domain space AD value
T<double> P; // range space AD value
// choose the polynomial coefficients
CppAD::uniform_01(size, a);
// AD copy of the polynomial coefficients
CppAD::vector< T<double> > A(size);
for(i = 0; i < size; i++)
A[i] = a[i];
// ------------------------------------------------------
while(repeat--)
{ // get the next argument value
CppAD::uniform_01(1, z);
// independent variable value
Z = z[0]; // argument value
Z[1] = 1; // argument first order Taylor coefficient
// AD computation of the dependent variable
P = CppAD::Poly(0, A, Z);
// Taylor-expand P to degree one
P.eval(2);
// second derivative is twice second order Taylor coefficient
ddp[0] = 2. * P[2];
// Free DAG corresponding to P does not seem to improve speed.
// Probably because it gets freed the next time P is assigned.
// P.reset();
}
// ------------------------------------------------------
return true;
}