/* nag_complex_eigensystem_sel (f02gcc) Example Program. * * Copyright 1998 Numerical Algorithms Group. * * Mark 5, 1998. * Mark 8 revised, 2004. * */ #include #include #include #include #define MMAX 3 #define A(I,J) a[(I)*tda + J] #define V(I,J) v[(I)*tdv + J] int main(void) { Complex *a=0, *v=0, *w=0; Integer exit_status=0, i, j, m, mest=MMAX, n, tda, tdv; NagError fail; double wl, wu; INIT_FAIL(fail); Vprintf("nag_complex_eigensystem_sel (f02gcc) Example Program Results\n"); /* Skip heading in data file */ Vscanf("%*[^\n]"); Vscanf("%ld%lf%lf%*[^\n] ",&n, &wl, &wu); if (n>=0) { if ( !( a = NAG_ALLOC(n*n, Complex)) || !( v = NAG_ALLOC(n*mest, Complex)) || !( w = NAG_ALLOC(n, Complex)) ) { Vprintf("Allocation failure\n"); exit_status = -1; goto END; } tda = n; tdv = mest; } else { Vprintf("Invalid n.\n"); exit_status = 1; return exit_status; } /* Read a from data file */ for (i = 0; i < n; ++i) for (j = 0; j < n; ++j) Vscanf(" ( %lf, %lf ) ",&A(i,j).re,&A(i,j).im); /* Compute selected eigenvalues and eigenvectors of A */ /* nag_complex_eigensystem_sel (f02gcc). * Computes selected eigenvalues and eigenvectors of a * complex general matrix */ nag_complex_eigensystem_sel(Nag_Select_Modulus, n, a, tda, wl, wu, mest, &m, w, v, tdv, &fail); if (fail.code != NE_NOERROR) { Vprintf("Error from nag_complex_eigensystem_sel (f02gcc).\n%s\n", fail.message); exit_status = 1; goto END; } Vprintf("\n\nEigenvalues\n\n"); for (i = 0; i < m; ++i) Vprintf("(%7.4f, %7.4f)%s",w[i].re, w[i].im, (i+1)%2 == 0 ? "\n" : " "); Vprintf("\nEigenvectors\n"); for (i=1; i<=m; i++) Vprintf("%15ld%s", i, i%m == 0 ?"\n" : ""); for (i = 0; i < n; i++) { Vprintf("%ld ", i + 1); for (j = 0; j < m; j++) Vprintf("(%8.4f, %8.4f)%s", V(i,j).re, V(i,j).im, (j + 1)%m == 0 ? "\n":" "); } END: if (a) NAG_FREE(a); if (v) NAG_FREE(v); if (w) NAG_FREE(w); return exit_status; }