/* nag_1d_spline_evaluate (e02bbc) Example Program.
*
* Copyright 2017 Numerical Algorithms Group.
*
* Mark 26.1, 2017.
*
*/

#include <nag.h>
#include <stdio.h>
#include <nag_stdlib.h>
#include <nage02.h>

int main(void)
{
Integer exit_status = 0, j, m, ncap, ncap7, r;
Nag_Spline spline;
double a, b, s, x;
NagError fail;

INIT_FAIL(fail);

/* Initialize spline */
spline.lamda = 0;
spline.c = 0;

printf("nag_1d_spline_evaluate (e02bbc) Example Program Results\n");
scanf("%*[^\n]"); /* Skip heading in data file */
while (scanf("%" NAG_IFMT "", &m) != EOF)
{
if (m <= 0) {
printf("Invalid m.\n");
exit_status = 1;
return exit_status;
}
scanf("%" NAG_IFMT "", &ncap);
ncap7 = ncap + 7;
if (ncap > 0) {
spline.n = ncap7;
if (!(spline.c = NAG_ALLOC(ncap7, double)) ||
!(spline.lamda = NAG_ALLOC(ncap7, double)))
{
printf("Allocation failure\n");
exit_status = -1;
goto END;
}
}
else {
printf("Invalid ncap.\n");
exit_status = 1;
return exit_status;
}
for (j = 0; j < ncap7; j++)
scanf("%lf", &(spline.lamda[j]));
for (j = 0; j < ncap + 3; j++)
scanf("%lf", &(spline.c[j]));
a = spline.lamda;
b = spline.lamda[ncap + 3];
printf("Augmented set of knots stored in spline.lamda:\n");
for (j = 0; j < ncap7; j++)
printf("%10.4f%s", spline.lamda[j],
(j % 6 == 5 || j == ncap7 - 1) ? "\n" : " ");
printf("\nB-spline coefficients stored in spline.c\n\n");
for (j = 0; j < ncap + 3; j++)
printf("%10.4f%s", spline.c[j],
(j % 6 == 5 || j == ncap + 2) ? "\n" : " ");
printf("\n      x         Value of cubic spline\n\n");
for (r = 1; r <= m; ++r) {
x = ((double) (m - r) * a + (double) (r - 1) * b) / (double) (m - 1);
/* nag_1d_spline_evaluate (e02bbc).
* Evaluation of fitted cubic spline, function only
*/
nag_1d_spline_evaluate(x, &s, &spline, &fail);
if (fail.code != NE_NOERROR) {
printf("Error from nag_1d_spline_evaluate (e02bbc).\n%s\n",
fail.message);
exit_status = 1;
goto END;
}
printf("%10.4f%15.4f\n", x, s);
}
NAG_FREE(spline.c);
NAG_FREE(spline.lamda);
}
END:
return exit_status;
}