/* nag_2d_spline_eval(e02dec) Example Program
 *
 * Copyright 1991 Numerical Algorithms Group.
 *
 * Mark 2, 1991.
 */

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

#define MMAX 20

int main(void)
{
  Integer i, m;
  double x[MMAX], y[MMAX], ff[MMAX];
  Nag_2dSpline spline;

  Vprintf("e02dec Example Program Results\n");
  Vscanf("%*[^\n]"); /* Skip heading in data file */
  /* Read m, the number of spline evaluation points. */
  Vscanf("%ld",&m);
  if (m<=MMAX)
    {
      /* Read nx and ny, the number of knots in the x and y directions. */
      Vscanf("%ld%ld",&(spline.nx),&(spline.ny));
      spline.c = NAG_ALLOC((spline.nx-4)*(spline.ny-4), double);
      spline.lamda = NAG_ALLOC(spline.nx, double);
      spline.mu = NAG_ALLOC(spline.ny, double);
      if (spline.c != (double *)0 && spline.lamda != (double *)0
          && spline.mu != (double *)0)
        {

          /* read the knots lamda[0] .. lamda[nx-1] and mu[0] .. mu[ny-1]. */
          for (i=0; i<spline.nx; i++)
            Vscanf("%lf",&(spline.lamda[i]));
          for (i=0; i<spline.ny;  i++)
            Vscanf("%lf",&(spline.mu[i]));
          /* Read c, the bicubic spline coefficients. */
          for (i=0; i<(spline.nx-4)*(spline.ny-4);
               Vscanf("%lf",&(spline.c[i])), i++);
          /* Read the x and y co-ordinates of the evaluation points. */
          for (i=0; i<m; i++)
            Vscanf("%lf%lf",&x[i],&y[i]);
          /* Evaluate the spline at the m points. */
          e02dec(m, x, y, ff, &spline, NAGERR_DEFAULT);
          /* Print the results. */
          Vprintf("      i          x[i]       y[i]       ff[i]\n");
          for (i=0; i<m; i++)
            Vprintf("%7ld    %11.3f%11.3f%11.3f\n",i,x[i],y[i],ff[i]);
          NAG_FREE(spline.lamda);
          NAG_FREE(spline.mu);
          NAG_FREE(spline.c);
          return EXIT_SUCCESS;
        }
      else
        {
          Vfprintf(stderr,"Storage allocation failed.\n");
          return EXIT_FAILURE;
        }
    }
  else
    {
      Vfprintf(stderr, "m is out of range: m = %5ld\n",m);
      return EXIT_FAILURE;
    }
}