/* nag_zgeev (f08nnc) Example Program. * * Copyright 2011 Numerical Algorithms Group. * * Mark 23, 2011. */ #include #include #include #include #include int main(void) { /* Scalars */ Integer exit_status = 0, i, j, n, pda, pdvr; /* Arrays */ Complex *a = 0, *vr = 0, *w = 0; Complex dummy[1]; /* Nag Types */ NagError fail; Nag_OrderType order; #ifdef NAG_COLUMN_MAJOR #define A(I, J) a[(J - 1) * pda + I - 1] #define VR(I, J) vr[(J)*pdvr + I] order = Nag_ColMajor; #else #define A(I, J) a[(I - 1) * pda + J - 1] #define VR(I, J) vr[(I)*pdvr + J] order = Nag_RowMajor; #endif INIT_FAIL(fail); printf("nag_zgeev (f08nnc) Example Program Results\n\n"); /* Skip heading in data file */ scanf("%*[^\n]"); scanf("%ld%*[^\n]", &n); pda = n; pdvr = n; /* Allocate memory */ if (!(a = NAG_ALLOC(n * n, Complex)) || !(vr = NAG_ALLOC(n * n, Complex)) || !(w = NAG_ALLOC(n, Complex))) { printf("Allocation failure\n"); exit_status = -1; goto END; } /* Read the matrix A from data file */ for (i = 1; i <= n; ++i) for (j = 1; j <= n; ++j) scanf(" ( %lf , %lf )", &A(i, j).re, &A(i, j).im); scanf("%*[^\n]"); /* Compute the eigenvalues and right eigenvectors of A using nag_zgeev (f08nnc). */ nag_zgeev(order, Nag_NotLeftVecs, Nag_RightVecs, n, a, pda, w, dummy, 1, vr, pdvr, &fail); if (fail.code != NE_NOERROR) { printf("Error from nag_zgeev (f08nnc).\n%s\n", fail.message); exit_status = 1; goto END; } /* Print eigenvalues and right eigenvectors. */ for (j = 0; j < n; ++j) { printf("\nEigenvalue %3ld = ", j+1); if (w[j].im == 0.0) printf("%13.4e\n", w[j].re); else printf(" (%11.4e, %11.4e)\n", w[j].re, w[j].im); printf("\nEigenvector %2ld\n", j+1); for (i = 0; i < n; ++i) printf("%18s(%11.4e, %11.4e)\n", "", VR(i, j).re, VR(i, j).im); printf("\n"); } END: if (a) NAG_FREE(a); if (vr) NAG_FREE(vr); if (w) NAG_FREE(w); return exit_status; } #undef A