/* nag_fft_multiple_qtr_sine (c06hcc) Example Program.
 *
 * Copyright 2014 Numerical Algorithms Group.
 *
 * Mark 2, 1991.
 * Mark 8 revised, 2004.
 */

#include <nag.h>
#include <stdio.h>
#include <nag_stdlib.h>
#include <nagc06.h>

#define X(I, J) x[(I) *n + (J)]

int main(void)
{
  Integer  exit_status = 0, i, j, m, n;
  double   *trig = 0, *x = 0;
  NagError fail;

  INIT_FAIL(fail);

  printf(
          "nag_fft_multiple_qtr_sine (c06hcc) Example Program Results\n");
  scanf(" %*[^\n]");    /* Skip heading in data file */
  while (scanf("%ld %ld", &m, &n) != EOF)
    {
      if (m >= 1 && n >= 1)
        {
          if (!(trig = NAG_ALLOC(2*n, double)) ||
              !(x = NAG_ALLOC(m*n, double)))
            {
              printf("Allocation failure\n");
              exit_status = -1;
              goto END;
            }
        }
      else
        {
          printf("\nInvalid m or n.\n");
          exit_status = 1;
          return exit_status;
        }
      scanf(" %*[^\n]"); /* Skip text in data file */
      scanf(" %*[^\n]");
      for (i = 0; i < m; ++i)
        for (j = 0; j < n; ++j)
          scanf("%lf", &X(i, j));
      printf("\nOriginal data values\n\n");
      for (i = 0; i < m; ++i)
        {
          for (j = 0; j < n; ++j)
            printf(" %10.4f%s", X(i, j),
                    (j%7 == 6 && j != n-1?"\n":""));
          printf("\n");
        }
      /* Initialise trig array */
      /* nag_fft_init_trig (c06gzc).
       * Initialization function for other c06 functions
       */
      nag_fft_init_trig(n, trig, &fail);
      if (fail.code != NE_NOERROR)
        {
          printf("Error from nag_fft_init_trig (c06gzc).\n%s\n",
                  fail.message);
          exit_status = 1;
          goto END;
        }

      /* Compute transform */
      /* nag_fft_multiple_qtr_sine (c06hcc).
       * Discrete quarter-wave sine transform
       */
      nag_fft_multiple_qtr_sine(Nag_ForwardTransform, m, n, x, trig, &fail);
      if (fail.code != NE_NOERROR)
        {
          printf(
                  "Error from nag_fft_multiple_qtr_sine (c06hcc).\n%s\n",
                  fail.message);
          exit_status = 1;
          goto END;
        }

      printf("\nDiscrete quarter-wave Fourier sine transforms\n\n");
      for (i = 0; i < m; ++i)
        {
          for (j = 0; j < n; ++j)
            printf(" %10.4f%s", X(i, j),
                    (j%7 == 6 && j != n-1?"\n":""));
          printf("\n");
        }
      /* Compute inverse transform */
      /* nag_fft_multiple_qtr_sine (c06hcc), see above. */
      nag_fft_multiple_qtr_sine(Nag_BackwardTransform, m, n, x, trig, &fail);
      if (fail.code != NE_NOERROR)
        {
          printf(
                  "Error from nag_fft_multiple_qtr_sine (c06hcc).\n%s\n",
                  fail.message);
          exit_status = 1;
          goto END;
        }

      printf("\nOriginal data as restored by inverse transform\n\n");
      for (i = 0; i < m; ++i)
        {
          for (j = 0; j < n; ++j)
            printf(" %10.4f%s", X(i, j),
                    (j%7 == 6 && j != n-1?"\n":""));
          printf("\n");
        }

 END:
      NAG_FREE(trig);
      NAG_FREE(x);
    }

  return exit_status;
}