/* nag_fft_3d (c06pxc) Example Program. * * Copyright 2002 Numerical Algorithms Group. * * Mark 7, 2002. */ #include #include #include #include #include #ifdef __cplusplus extern "C" { #endif Integer NAG_CALL writex(Integer n1,Integer n2,Integer n3,Complex *x); #ifdef __cplusplus } #endif Integer NAG_CALL writex(Integer n1,Integer n2,Integer n3,Complex *x) { /* Routine to print 3D matrix in 2D slices. */ Integer k; NagError fail; INIT_FAIL(fail); for (k=1;k<=n3;k++) { char title[30]; sprintf(title,"X(i,j,k) for k = %"NAG_IFMT,k); fflush(stdout); nag_gen_complx_mat_print_comp(Nag_ColMajor, Nag_GeneralMatrix, Nag_NonUnitDiag, n1, n2, &x[(k-1)*n1*n2], n1, Nag_BracketForm, "%6.3f", title, Nag_NoLabels, 0, Nag_NoLabels, 0, 90, 0, 0, &fail); printf("\n"); } if (fail.code != NE_NOERROR) { printf( "Error from nag_gen_complx_mat_print_comp (x04dbc).\n%s\n", fail.message); return 1; } return 0; } int main(void) { /* Scalars */ Integer i, j, k, n1, n2, n3; Integer exit_status = 0; NagError fail; /* Arrays */ Complex *x = 0; #define X(I, J, K) x[(K-1)*n2*n1 + (J-1)*n1 + I - 1] INIT_FAIL(fail); printf("nag_fft_3d (c06pxc) Example Program Results\n"); /* Skip heading in data file */ scanf("%*[^\n]"); scanf("%ld%ld%ld", &n1, &n2, &n3); scanf("%*[^\n]"); if (n1*n2*n3 >= 1) { /* Allocate memory */ if (!(x = NAG_ALLOC(n1 * n2 * n3, Complex))) { printf("Allocation failure\n"); exit_status = -1; goto END; } /* Read in complex data and print out. */ for (k = 1; k <= n3; ++k) { for (i = 1; i <= n1; ++i) { for (j = 1; j <= n2; ++j) { scanf(" ( %lf, %lf ) ", &X(i, j, k).re, &X(i, j, k).im); } } } printf("\nOriginal data values\n\n"); exit_status = writex(n1,n2,n3,x); if (exit_status != 0) { goto END; } /* Compute transform */ /* nag_fft_3d (c06pxc). * Three-dimensional complex discrete Fourier transform, * complex data format */ nag_fft_3d(Nag_ForwardTransform, n1, n2, n3, x, &fail); if (fail.code != NE_NOERROR) { printf("Error from nag_fft_3d (c06pxc).\n%s\n", fail.message); exit_status = 1; goto END; } printf("\nComponents of discrete Fourier transforms\n\n"); exit_status = writex(n1,n2,n3,x); if (exit_status != 0) { goto END; } /* Compute inverse transform */ /* nag_fft_3d (c06pxc), see above. */ nag_fft_3d(Nag_BackwardTransform, n1, n2, n3, x, &fail); if (fail.code != NE_NOERROR) { printf("Error from nag_fft_3d (c06pxc).\n%s\n", fail.message); exit_status = 1; goto END; } printf("\nOriginal data as restored by inverse transform\n\n"); exit_status = writex(n1,n2,n3,x); } else printf("\nInvalid value of n1, n2 or n3.\n"); END: if (x) NAG_FREE(x); return exit_status; }