/* nag_1d_spline_evaluate (e02bbc) Example Program.

 *

 * Copyright 1991 Numerical Algorithms Group.

 *

 * Mark 2, 1991.

 *

 * Mark 3 revised, 1994.

 * Mark 8 revised, 2004.

 */



#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;

  NagError fail;

  Nag_Spline spline;

  double a, b, s, x;



  INIT_FAIL(fail);



  Vprintf("nag_1d_spline_evaluate (e02bbc) Example Program Results\n");

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

  while(scanf("%ld",&m) !=EOF)

    {

      if (m<=0)

        {

          Vprintf("Invalid m.\n");

          exit_status = 1;

          return exit_status;

        }

      Vscanf("%ld",&ncap);

      ncap7 = ncap+7;

      if (ncap>0)

        {

          spline.n = ncap7;

          if ( !( spline.c = NAG_ALLOC(ncap7, double)) ||

               !( spline.lamda = NAG_ALLOC(ncap7, double)) )

            {

              Vprintf("Allocation failure\n");

              exit_status = -1;

              goto END;

            }

        }

      else

        {

          Vprintf("Invalid ncap.\n");

          exit_status = 1;

          return exit_status;

        }

      for (j=0; j<ncap7; j++)

        Vscanf("%lf",&(spline.lamda[j]));

      for (j=0; j<ncap+3; j++)

        Vscanf("%lf",&(spline.c[j]));

      a = spline.lamda[3];

      b = spline.lamda[ncap+3];

      Vprintf("Augmented set of knots stored in spline.lamda:\n");

      for (j=0; j<ncap7; j++)

        Vprintf("%10.4f%s",spline.lamda[j],

                (j%6==5 || j==ncap7-1) ? "\n" : " ");

      Vprintf("\nB-spline coefficients stored in spline.c\n\n");

      for (j=0; j<ncap+3; j++)

        Vprintf("%10.4f%s",spline.c[j],

                (j%6==5 || j==ncap+2) ? "\n" : " ");

      Vprintf("\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)

            {

              Vprintf("Error from nag_1d_spline_evaluate (e02bbc).\n%s\n",

                      fail.message);

              exit_status = 1;

              goto END;

            }

          Vprintf("%10.4f%15.4f\n",x,s);

        }

      NAG_FREE(spline.c);

      NAG_FREE(spline.lamda);

    }

 END:

  return exit_status;

}