/* nag_smooth_spline_fit (g10abc) Example Program.
 *
 * Copyright 2000 Numerical Algorithms Group.
 *
 * Mark 6a revised, 2001.
 */

#include <stdio.h>
#include <nag.h>
#include <nagx04.h>
#include <nag_stdlib.h>
#include <nagg10.h>

int main(int argc, char *argv[])
{
  FILE              *fpin, *fpout;
  Integer           exit_status = 0, i, n, nord;
  double            df, rho, rss;
  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[40];
  Nag_SmoothFitType mode;
  Nag_Boolean       weight;
  NagError          fail;

  INIT_FAIL(fail);

  /* Check for command-line IO options */
  fpin = nag_example_file_io(argc, argv, "-data", NULL);
  fpout = nag_example_file_io(argc, argv, "-results", NULL);
  fprintf(fpout, "nag_smooth_spline_fit (g10abc) Example Program Results\n");

  /* Skip heading in data file */
  fscanf(fpin, "%*[^\n]");

  fscanf(fpin, "%ld", &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)))
    {
      fprintf(fpout, "Allocation failure\n");
      exit_status = -1;
      goto END;
    }

  fscanf(fpin, "%s", 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);
  fscanf(fpin, "%s", nag_enum_arg);
  weight = (Nag_Boolean) nag_enum_name_to_value(nag_enum_arg);

  fscanf(fpin, "%lf", &rho);
  if (!weight)
    {
      for (i = 1; i <= n; ++i)
        fscanf(fpin, "%lf %lf ", &x[i - 1], &y[i - 1]);
      wtptr = 0;
    }
  else
    {
      for (i = 1; i <= n; ++i)
        fscanf(fpin, "%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)
    {
      fprintf(fpout, "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)
    {
      fprintf(fpout, "Error from nag_smooth_spline_fit (g10abc).\n%s\n",
              fail.message);
      exit_status = 1;
      goto END;
    }

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

 END:
  if (fpin != stdin) fclose(fpin);
  if (fpout != stdout) fclose(fpout);
  if (coeff) NAG_FREE(coeff);
  if (h) NAG_FREE(h);
  if (res) NAG_FREE(res);
  if (x) NAG_FREE(x);
  if (y) NAG_FREE(y);
  if (weights) NAG_FREE(weights);
  if (xord) NAG_FREE(xord);
  if (yord) NAG_FREE(yord);
  if (wwt) NAG_FREE(wwt);
  if (yhat) NAG_FREE(yhat);
  if (comm_ar) NAG_FREE(comm_ar);

  return exit_status;
}