/* S01BA_A1W_F C++ Header Example Program.
*
* Copyright 2019 Numerical Algorithms Group.
* Mark 27, 2019.
*/
#include <nag.h>
#include <nagad.h>
#include <stdio.h>
#include <nag_stdlib.h>
#include <string>
#include <iostream>
using namespace std;
int main(void)
{
int exit_status = 0;
// Input and output variables
nagad_a1w_w_rtype x, y;
cout << "S01BA_A1W_F C++ Header Example Program Results\n\n";
// Skip heading in data file
string mystr;
getline (cin, mystr);
// Read number of x values
Integer n;
cin >> n;
// Create AD tape
nagad_a1w_ir_create();
// Create AD configuration data object
Integer ifail = -1;
void *ad_handle = 0;
x10aa_a1w_f_(ad_handle,ifail);
if (ifail != 0) {
exit_status = 1;
goto END;
}
cout << " x y=ln(1+x) dy/dx\n";
cout.setf(ios::scientific,ios::floatfield);
cout.setf(ios::right);
cout.precision(4);
// Loop over x values
for (Integer i = 0; i < n; ++i) {
// Read next x
double xr;
cin >> xr;
x.value = xr;
x.id = 0;
// Register x, i.e. differentiate w.r.t. x
nagad_a1w_ir_register_variable(&x);
// Call NAG AD Routine
ifail = -1;
s01ba_a1w_f_(ad_handle,x,y,ifail);
if (ifail != 0) {
exit_status = 2;
goto END;
}
// Reset adjoints, increment y, and evaluate adjoint of y w.r.t. x
nagad_a1w_ir_zero_adjoints();
double inc = 1.0;
nagad_a1w_inc_derivative(&y,inc);
ifail = -1;
nagad_a1w_ir_interpret_adjoint(ifail);
if (ifail != 0) {
exit_status = 3;
goto END;
}
// Get derivative, dydx and output values
double dydx;
dydx = nagad_a1w_get_derivative(x);
cout.width(12); cout << x.value;
cout.width(12); cout << y.value;
cout.width(12); cout << dydx << endl;
}
// Remove computational data object and tape
x10ab_a1w_f_(ad_handle,ifail);
nagad_a1w_ir_remove();
END:
return exit_status;
}