/* nag_smooth_spline_fit (g10abc) Example Program.
*
* Copyright 2017 Numerical Algorithms Group.
*
* Mark 26.1, 2017.
*/

#include <stdio.h>
#include <nag.h>
#include <nag_stdlib.h>
#include <nagg10.h>

int main(void)
{
Integer exit_status = 0, i, n, nord;
double *coeff = 0, *comm_ar = 0, *h = 0, *res = 0, *weights = 0;
double *wtptr, *wwt = 0, *x = 0, *xord = 0, *y = 0, *yhat = 0;
double *yord = 0;
char nag_enum_arg;
Nag_SmoothFitType mode;
Nag_Boolean weight;
NagError fail;

INIT_FAIL(fail);

printf("nag_smooth_spline_fit (g10abc) Example Program Results\n");

/* Skip heading in data file */
scanf("%*[^\n]");
scanf("%" NAG_IFMT "", &n);
if (!(coeff = NAG_ALLOC((n - 1) * 3, double))
|| !(h = NAG_ALLOC(n, double))
|| !(res = NAG_ALLOC(n, double))
|| !(x = NAG_ALLOC(n, double))
|| !(y = NAG_ALLOC(n, double))
|| !(weights = NAG_ALLOC(n, double))
|| !(xord = NAG_ALLOC(n, double))
|| !(yord = NAG_ALLOC(n, double))
|| !(wwt = NAG_ALLOC(n, double))
|| !(yhat = NAG_ALLOC(n, double))
|| !(comm_ar = NAG_ALLOC(9 * n + 14, double)))
{
printf("Allocation failure\n");
exit_status = -1;
goto END;
}
scanf("%39s", nag_enum_arg);
/* nag_enum_name_to_value (x04nac).
* Converts NAG enum member name to value
*/
mode = (Nag_SmoothFitType) nag_enum_name_to_value(nag_enum_arg);
scanf("%39s", nag_enum_arg);
weight = (Nag_Boolean) nag_enum_name_to_value(nag_enum_arg);
scanf("%lf", &rho);
if (!weight) {
for (i = 1; i <= n; ++i)
scanf("%lf %lf ", &x[i - 1], &y[i - 1]);
wtptr = 0;
}
else {
for (i = 1; i <= n; ++i)
scanf("%lf %lf %lf", &x[i - 1], &y[i - 1], &weights[i - 1]);
wtptr = weights;
}
/* Sort data into increasing X and */
/* remove tied observations and weight accordingly */
/* nag_order_data (g10zac).
* Reorder data to give ordered distinct observations
*/
nag_order_data(n, x, y, wtptr, &nord, xord, yord, wwt, &rss, &fail);
if (fail.code != NE_NOERROR) {
printf("Error from nag_order_data (g10zac).\n%s\n", fail.message);
exit_status = 1;
goto END;
}

/* Fit cubic spline */
/* nag_smooth_spline_fit (g10abc).
* Fit cubic smoothing spline, smoothing parameter given
*/
nag_smooth_spline_fit(mode, nord, xord, yord, wwt, rho, yhat, coeff,
&rss, &df, res, h, comm_ar, &fail);
if (fail.code != NE_NOERROR) {
printf("Error from nag_smooth_spline_fit (g10abc).\n%s\n", fail.message);
exit_status = 1;
goto END;
}

/* Print results */
printf("\n");
printf("%s%10.3f\n", " rho  = ", rho);
printf("\n");
printf("%s%10.3f\n", " Residual sum of squares  = ", rss);
printf("%s%10.3f\n", " Degrees of freedom       = ", df);
printf("\n");
printf("%s\n", " Ordered input data     Output results");
printf("\n");
printf("%s\n", "    x       y           Fitted Values");
printf("\n");
for (i = 1; i <= nord; ++i) {
printf("%8.4f %8.4f      %8.4f\n", xord[i - 1], yord[i - 1], yhat[i - 1]);
}

END:
NAG_FREE(coeff);
NAG_FREE(h);
NAG_FREE(res);
NAG_FREE(x);
NAG_FREE(y);
NAG_FREE(weights);
NAG_FREE(xord);
NAG_FREE(yord);
NAG_FREE(wwt);
NAG_FREE(yhat);
NAG_FREE(comm_ar);

return exit_status;
}