/* nag_fit_dim2_cheb_eval (e02cbc) Example Program.
*
* Copyright 2024 Numerical Algorithms Group.
*
* Mark 30.0, 2024.
*/
#include <nag.h>
#include <stdio.h>
int main(void) {
/* Scalars */
double x1, xm, xmax, xmin, y, ymax, ymin;
Integer exit_status, i, j, k, l, m, n, ncoef, one;
NagError fail;
/* Arrays */
double *a = 0, *ff = 0, *x = 0;
INIT_FAIL(fail);
exit_status = 0;
printf("nag_fit_dim2_cheb_eval (e02cbc) Example Program Results\n");
/* Skip heading in data file */
scanf("%*[^\n] ");
while (scanf("%" NAG_IFMT "%" NAG_IFMT "%" NAG_IFMT "%*[^\n] ", &n, &k, &l) !=
EOF)
{
/* Allocate array a */
ncoef = (k + 1) * (l + 1);
if (!(a = NAG_ALLOC(ncoef, double))) {
printf("Allocation failure\n");
exit_status = -1;
goto END;
}
for (i = 0; i < ncoef; ++i)
scanf("%lf", &a[i]);
scanf("%*[^\n] ");
scanf("%lf%lf%*[^\n] ", &ymin, &ymax);
for (i = 0; i < n; ++i) {
scanf("%lf%" NAG_IFMT "%lf%lf%lf%lf%*[^\n] ", &y, &m, &xmin, &xmax, &x1,
&xm);
/* Allocate arrays x and ff */
if (!(x = NAG_ALLOC(m, double)) || !(ff = NAG_ALLOC(m, double))) {
printf("Allocation failure\n");
exit_status = -1;
goto END;
}
for (j = 0; j < m; ++j)
x[j] = x1 + (xm - x1) * (double)j / (double)(m - 1);
one = 1;
/* nag_fit_dim2_cheb_eval (e02cbc).
* Evaluation of fitted polynomial in two variables
*/
nag_fit_dim2_cheb_eval(one, m, k, l, x, xmin, xmax, y, ymin, ymax, ff, a,
&fail);
if (fail.code != NE_NOERROR) {
printf("Error from nag_fit_dim2_cheb_eval (e02cbc).\n%s\n",
fail.message);
exit_status = 1;
goto END;
}
printf("\n");
printf("y = %13.4e\n", y);
printf("\n");
printf(" i x(i) Poly(x(i),y)\n");
for (j = 0; j < m; ++j)
printf("%3" NAG_IFMT "%13.4e%13.4e\n", j, x[j], ff[j]);
NAG_FREE(ff);
NAG_FREE(x);
}
NAG_FREE(a);
}
END:
NAG_FREE(a);
NAG_FREE(ff);
NAG_FREE(x);
return exit_status;
}