/* nag_convolution_real (c06ekc) Example Program. * * Copyright 1990 Numerical Algorithms Group. * * Mark 1, 1990. * Mark 8 revised, 2004. */ #include #include #include #include int main(void) { Integer exit_status = 0, j, n; NagError fail; double *xa = 0, *xb = 0, *ya = 0, *yb = 0; INIT_FAIL(fail); printf("nag_convolution_real (c06ekc) Example Program Results\n"); /* Skip heading in data file */ scanf("%*[^\n]"); while (scanf("%ld", &n) != EOF) { if (n > 1) { if (!(xa = NAG_ALLOC(n, double)) || !(xb = NAG_ALLOC(n, double)) || !(ya = NAG_ALLOC(n, double)) || !(yb = NAG_ALLOC(n, double))) { printf("Allocation failure\n"); exit_status = -1; goto END; } } else { printf("Invalid n.\n"); exit_status = 1; return exit_status; } for (j = 0; j < n; ++j) { scanf("%lf%lf", &xa[j], &ya[j]); xb[j] = xa[j]; yb[j] = ya[j]; } /* nag_convolution_real (c06ekc). * Circular convolution or correlation of two real vectors */ nag_convolution_real(Nag_Convolution, n, xa, ya, &fail); if (fail.code != NE_NOERROR) { printf("Error from nag_convolution_real (c06ekc).\n%s\n", fail.message); exit_status = 1; goto END; } /* nag_convolution_real (c06ekc), see above. */ nag_convolution_real(Nag_Correlation, n, xb, yb, &fail); if (fail.code != NE_NOERROR) { printf("Error from nag_convolution_real (c06ekc).\n%s\n", fail.message); exit_status = 1; goto END; } printf("\n Convolution Correlation\n\n"); for (j = 0; j < n; ++j) printf("%5ld %13.5f %13.5f\n", j, xa[j], xb[j]); END: NAG_FREE(xa); NAG_FREE(xb); NAG_FREE(ya); NAG_FREE(yb); } return exit_status; }