NAG Library Manual, Mark 30.1
Interfaces:  FL   CL   CPP   AD 

NAG CL Interface Introduction
Example description
/* nag_sum_fft_complex_2d (c06puc) Example Program.
 *
 * Copyright 2024 Numerical Algorithms Group.
 *
 * Mark 30.1, 2024.
 */

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

int main(void) {
  /* Scalars */
  Integer exit_status = 0, i, m, n;
  /* Arrays */
  Complex *x = 0;
  char title[60];
  /* Nag Types */
  NagError fail;

  INIT_FAIL(fail);

  printf("nag_sum_fft_complex_2d (c06puc) Example Program Results\n");
  fflush(stdout);

  /* Read dimensions of array and array values from data file. */
  scanf("%*[^\n] %" NAG_IFMT "%" NAG_IFMT "%*[^\n]", &m, &n);

  if (!(x = NAG_ALLOC(m * n, Complex))) {
    printf("Allocation failure\n");
    exit_status = -1;
    goto END;
  }
  /* The data is read in order as n groups of m complex values. */
  for (i = 0; i < m * n; i++)
    scanf(" ( %lf , %lf ) ", &x[i].re, &x[i].im);

    /* nag_file_print_matrix_complex_gen_comp (x04dbc).
     * Print complex general matrix (comprehensive).
     * The data can be viewed as an n-by-m matrix stored in row order, or as an
     * m-by-n matrix stored in column order. We choose the former here.
     */
  sprintf(title, "\n Original data values\n");
  nag_file_print_matrix_complex_gen_comp(
      Nag_RowMajor, Nag_GeneralMatrix, Nag_NonUnitDiag, n, m, x, m,
      Nag_BracketForm, "%6.3f", title, Nag_NoLabels, 0, Nag_NoLabels, 0, 80, 0,
      NULL, &fail);
  if (fail.code != NE_NOERROR) {
    printf("Error from nag_file_print_matrix_complex_gen_comp (x04dbc).\n%s\n",
           fail.message);
    exit_status = 1;
    goto END;
  }

  /* Compute two-dimensional complex discrete Fourier transform using
   * nag_sum_fft_complex_2d (c06puc) and print out.
   */
  nag_sum_fft_complex_2d(Nag_ForwardTransform, m, n, x, &fail);
  if (fail.code != NE_NOERROR) {
    printf("Error from nag_sum_fft_complex_2d (c06puc).\n%s\n", fail.message);
    exit_status = 2;
    goto END;
  }
  sprintf(title, "\n Components of discrete Fourier transform\n");
  nag_file_print_matrix_complex_gen_comp(
      Nag_RowMajor, Nag_GeneralMatrix, Nag_NonUnitDiag, n, m, x, m,
      Nag_BracketForm, "%6.3f", title, Nag_NoLabels, 0, Nag_NoLabels, 0, 80, 0,
      NULL, &fail);
  if (fail.code != NE_NOERROR) {
    printf("Error from nag_file_print_matrix_complex_gen_comp (x04dbc).\n%s\n",
           fail.message);
    exit_status = 3;
    goto END;
  }

  /* Compute two-dimensional complex discrete Fourier backward transform using
   * nag_sum_fft_complex_2d (c06puc) and print out.
   */
  nag_sum_fft_complex_2d(Nag_BackwardTransform, m, n, x, &fail);
  if (fail.code != NE_NOERROR) {
    printf("Error from nag_sum_fft_complex_2d (c06puc).\n%s\n", fail.message);
    exit_status = 4;
    goto END;
  }
  sprintf(title, "\n Original sequence as restored by inverse transform\n");
  nag_file_print_matrix_complex_gen_comp(
      Nag_RowMajor, Nag_GeneralMatrix, Nag_NonUnitDiag, n, m, x, m,
      Nag_BracketForm, "%6.3f", title, Nag_NoLabels, 0, Nag_NoLabels, 0, 80, 0,
      NULL, &fail);
  if (fail.code != NE_NOERROR) {
    printf("Error from nag_file_print_matrix_complex_gen_comp (x04dbc).\n%s\n",
           fail.message);
    exit_status = 5;
  }

END:
  NAG_FREE(x);
  return exit_status;
}