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

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

int main (void)
{
  Integer exit_status=0, i, n, nord;
  NagError fail;
  Nag_SmoothFitType mode_enum;
  char mode[2], weight[2];
  double *coeff=0, *comm_ar=0, df, *h=0, *res=0, rho, rss, *weights=0, *wtptr;
  double *wwt=0, *x=0, *xord=0, *y=0, *yhat=0, *yord=0;

  INIT_FAIL(fail);
  Vprintf("nag_smooth_spline_fit (g10abc) Example Program Results\n");

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

  Vscanf("%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)))
    {
      Vprintf("Allocation failure\n");
      exit_status = -1;
      goto END;
    }

  Vscanf(" %s  %s ", mode, weight);
  if (*mode == 'P')
    mode_enum = Nag_SmoothFitPartial;
  else if (*mode == 'Q')
    mode_enum = Nag_SmoothFitQuick;
  else if (*mode == 'F')
    mode_enum = Nag_SmoothFitFull;
  else
    mode_enum = (Nag_SmoothFitType)-999;

  Vscanf("%lf", &rho);
  if (*weight == 'U' )
    {
      for (i = 1; i <= n; ++i)
        Vscanf("%lf %lf ", &x[i - 1], &y[i - 1]);
      wtptr = 0;
    }
  else
    {
      for (i = 1; i <= n; ++i)
        Vscanf("%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)
    {
      Vprintf("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_enum, nord, xord, yord, wwt, rho, yhat, coeff,
                        &rss, &df, res, h, comm_ar, &fail);
  if (fail.code != NE_NOERROR)
    {
      Vprintf("Error from nag_smooth_spline_fit (g10abc).\n%s\n", fail.message);
      exit_status = 1;
      goto END;
    }


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