#include #include #include // Matrix as in Beyn, section 4.11 int M_function(complex double *target, const size_t m, const complex double z, void *no_params) { complex double d = 2*m - 4*z / (6*m); complex double od = -((double)m) - z / (6*m); memset(target, 0, m*m*sizeof(complex double)); for (int i = 0; i < m; ++i) { target[i*m + i] = d; if(i > 0) target[i*m + i-1] = od; if(i < m - 1) target[i*m + i+1] = od; } target[m*(m-1) + m-1] = d/2 + z/(z-1); return 0; } int main() { complex double z0 = 150+2*I; double Rx = 148, Ry = 148; int L = 10, N = 50, dim = 400; beyn_contour_t *contour = beyn_contour_ellipse(z0, Rx, Ry, N); beyn_result_t *result = beyn_solve(dim, L, M_function, NULL /*M_inv_Vhat_function*/, NULL /*params*/, contour, 1e-4, 0); printf("Found %zd eigenvalues:\n", result->neig); for (size_t i = 0; i < result->neig; ++i) { complex double eig = result->eigval[i]; printf("%zd: %g%+gj\n", i, creal(eig), cimag(eig)); } free(contour); beyn_result_free(result); return 0; }