/* nag_fft_2d_complex (c06fuc) Example Program. * * Copyright 1990 Numerical Algorithms Group. * * Mark 2 revised, 1992. * Mark 8 revised, 2004. */ #include #include #include #include int main(void) { Integer exit_status = 0, i, j, m, n; NagError fail; double *trigm = 0, *trign = 0, *x = 0, *y = 0; INIT_FAIL(fail); printf("nag_fft_2d_complex (c06fuc) Example Program Results\n"); /* Skip heading in data file */ scanf("%*[^\n]"); while (scanf("%ld%ld", &m, &n) != EOF) { if (m*n >= 1) { if (!(trigm = NAG_ALLOC(2*m, double)) || !(trign = NAG_ALLOC(2*n, double)) || !(x = NAG_ALLOC(m*n, double)) || !(y = 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 complex data and print out. */ for (j = 0; j < m; ++j) { for (i = 0; i < n; ++i) scanf("%lf", &x[j*n + i]); for (i = 0; i < n; ++i) scanf("%lf", &y[j*n + i]); } printf("\nOriginal data values\n\n"); for (j = 0; j < m; ++j) { printf("Real"); for (i = 0; i < n; ++i) printf("%10.4f%s", x[j*n + i], (i%6 == 5 && i != n-1?"\n ":"")); printf("\nImag"); for (i = 0; i < n; ++i) printf("%10.4f%s", y[j*n + i], (i%6 == 5 && i != n-1?"\n ":"")); printf("\n\n"); } /* Initialize trig arrays */ /* nag_fft_init_trig (c06gzc). * Initialization function for other c06 functions */ nag_fft_init_trig(m, trigm, &fail); if (fail.code != NE_NOERROR) { printf("Error from nag_fft_init_trig (c06gzc).\n%s\n", fail.message); exit_status = 1; goto END; } /* nag_fft_init_trig (c06gzc), see above. */ nag_fft_init_trig(n, trign, &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_2d_complex (c06fuc). * Two-dimensional complex discrete Fourier transform */ nag_fft_2d_complex(m, n, x, y, trigm, trign, &fail); if (fail.code != NE_NOERROR) { printf("Error from nag_fft_2d_complex (c06fuc).\n%s\n", fail.message); exit_status = 1; goto END; } printf("\nComponents of discrete Fourier transforms\n\n"); for (j = 0; j < m; ++j) { printf("Real"); for (i = 0; i < n; ++i) printf("%10.4f%s", x[j*n + i], (i%6 == 5 && i != n-1?"\n ":"")); printf("\nImag"); for (i = 0; i < n; ++i) printf("%10.4f%s", y[j*n + i], (i%6 == 5 && i != n-1?"\n ":"")); printf("\n\n"); } /* Compute inverse transform */ /* nag_conjugate_complex (c06gcc). * Complex conjugate of complex sequence */ nag_conjugate_complex(m*n, y, &fail); if (fail.code != NE_NOERROR) { printf("Error from nag_conjugate_complex (c06gcc).\n%s\n", fail.message); exit_status = 1; goto END; } /* nag_fft_2d_complex (c06fuc), see above. */ nag_fft_2d_complex(m, n, x, y, trigm, trign, &fail); if (fail.code != NE_NOERROR) { printf("Error from nag_fft_2d_complex (c06fuc).\n%s\n", fail.message); exit_status = 1; goto END; } /* nag_conjugate_complex (c06gcc), see above. */ nag_conjugate_complex(m*n, y, &fail); if (fail.code != NE_NOERROR) { printf("Error from nag_conjugate_complex (c06gcc).\n%s\n", fail.message); exit_status = 1; goto END; } printf("\nOriginal data as restored by inverse transform\n\n"); for (j = 0; j < m; ++j) { printf("Real"); for (i = 0; i < n; ++i) printf("%10.4f%s", x[j*n + i], (i%6 == 5 && i != n-1?"\n ":"")); printf("\nImag"); for (i = 0; i < n; ++i) printf("%10.4f%s", y[j*n + i], (i%6 == 5 && i != n-1?"\n ":"")); printf("\n\n"); } END: if (trigm) NAG_FREE(trigm); if (trign) NAG_FREE(trign); if (x) NAG_FREE(x); if (y) NAG_FREE(y); } return exit_status; }