/* nag_fft_multiple_real (c06fpc) Example Program.
 *
 * Copyright 2014 Numerical Algorithms Group.
 *
 * Mark 1, 1990.
 * Mark 8 revised, 2004.
 */

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

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

  INIT_FAIL(fail);

  printf("nag_fft_multiple_real (c06fpc) Example Program Results\n");
  /* Skip heading in data file */
  scanf("%*[^\n]");
  while (scanf("%ld%ld", &m, &n) != EOF)
    {
      if (m >= 1 && n >= 1)
        {
          if (!(trig = NAG_ALLOC(2*n, double)) ||
              !(u = NAG_ALLOC(m*n, double)) ||
              !(v = NAG_ALLOC(m*n, double)) ||
              !(x = NAG_ALLOC(m*n, double)))
            {
              printf("Allocation failure\n");
              exit_status = -1;
              goto END;
            }
        }
      else
        {
          printf("Invalid m or n.\n");
          exit_status = 1;
          return exit_status;
        }

      printf("\n\nm = %2ld  n = %2ld\n", m, n);
      /* Read in data and print out. */
      for (j = 0; j < m; ++j)
        for (i = 0; i < n; ++i)
          scanf("%lf", &x[j*n + i]);
      printf("\nOriginal data values\n\n");
      for (j = 0; j < m; ++j)
        {
          printf("    ");
          for (i = 0; i < n; ++i)
            printf("%10.4f%s", x[j*n + i],
                    (i%6 == 5 && i != n-1?"\n     ":""));
          printf("\n");
        }
      /* nag_fft_init_trig (c06gzc).
       * Initialization function for other c06 functions
       */
      nag_fft_init_trig(n, trig, &fail);  /* Initialise trig array */
      if (fail.code != NE_NOERROR)
        {
          printf("Error from nag_fft_init_trig (c06gzc).\n%s\n",
                  fail.message);
          exit_status = 1;
          goto END;
        }
      /* Calculate transforms */
      /* nag_fft_multiple_real (c06fpc).
       * Multiple one-dimensional real discrete Fourier transforms
       */
      nag_fft_multiple_real(m, n, x, trig, &fail);
      if (fail.code != NE_NOERROR)
        {
          printf("Error from nag_fft_multiple_real (c06fpc).\n%s\n",
                  fail.message);
          exit_status = 1;
          goto END;
        }
      printf("\nDiscrete Fourier transforms in Hermitian format\n\n");
      for (j = 0; j < m; ++j)
        {
          printf("    ");
          for (i = 0; i < n; ++i)
            printf("%10.4f%s", x[j*n + i],
                    (i%6 == 5 && i != n-1?"\n     ":""));
          printf("\n");
        }
      /* Calculate full complex form of Hermitian result */
      /* nag_multiple_hermitian_to_complex (c06gsc).
       * Convert Hermitian sequences to general complex sequences
       */
      nag_multiple_hermitian_to_complex(m, n, x, u, v, &fail);
      printf("\nFourier transforms in full complex form\n\n");
      for (j = 0; j < m; ++j)
        {
          printf("Real");
          for (i = 0; i < n; ++i)
            printf("%10.4f%s", u[j*n + i],
                    (i%6 == 5 && i != n-1?"\n     ":""));
          printf("\nImag");
          for (i = 0; i < n; ++i)
            printf("%10.4f%s", v[j*n + i],
                    (i%6 == 5 && i != n-1?"\n     ":""));
          printf("\n\n");
        }
      /* Calculate inverse transforms */
      /* Conjugate Hermitian sequences of transforms */
      /* nag_multiple_conjugate_hermitian (c06gqc).
       * Complex conjugate of multiple Hermitian sequences
       */
      nag_multiple_conjugate_hermitian(m, n, x, &fail);
      /* Transform to give inverse transforms */
      /* nag_fft_multiple_hermitian (c06fqc).
       * Multiple one-dimensional Hermitian discrete Fourier
       * transforms
       */
      nag_fft_multiple_hermitian(m, n, x, trig, &fail);
      printf("\nOriginal data as restored by inverse transform\n\n");
      for (j = 0; j < m; ++j)
        {
          printf("    ");
          for (i = 0; i < n; ++i)
            printf("%10.4f%s", x[j*n + i],
                    (i%6 == 5 && i != n-1?"\n     ":""));
          printf("\n");
        }
 END:
      NAG_FREE(trig);
      NAG_FREE(u);
      NAG_FREE(v);
      NAG_FREE(x);
    }
  return exit_status;
}