/* nag_real_eigenvalues (f02afc) Example Program. * * Copyright 1990 Numerical Algorithms Group. * * Mark 2 revised, 1992. * Mark 8 revised, 2004. */ #include #include #include #include #define COMPLEX(A) A.re, A.im #define A(I, J) a[(I) *tda + J] int main(void) { Complex *r = 0; Integer exit_status = 0, i, *iter = 0, j, n, tda; NagError fail; double *a = 0; INIT_FAIL(fail); printf("nag_real_eigenvalues (f02afc) Example Program Results\n"); /* Skip heading in data file */ scanf("%*[^\n]"); scanf("%ld", &n); if (n >= 1) { if (!(a = NAG_ALLOC(n*n, double)) || !(iter = NAG_ALLOC(n, Integer)) || !(r = NAG_ALLOC(n, Complex))) { printf("Allocation failure\n"); exit_status = -1; goto END; } tda = n; } else { printf("Invalid n.\n"); exit_status = 1; return exit_status; } for (i = 0; i < n; i++) for (j = 0; j < n; j++) scanf("%lf", &A(i, j)); /* nag_real_eigenvalues (f02afc). * All eigenvalues of real matrix */ nag_real_eigenvalues(n, a, tda, r, iter, &fail); if (fail.code != NE_NOERROR) { printf("Error from nag_real_eigenvalues (f02afc).\n%s\n", fail.message); exit_status = 1; goto END; } printf("Eigenvalues\n"); for (i = 0; i < n; i++) printf("( %7.3f , %7.3f ) \n", COMPLEX(r[i])); END: NAG_FREE(a); NAG_FREE(iter); NAG_FREE(r); return exit_status; }