2 #include <gsl/gsl_errno.h>
3 #include <gsl/gsl_matrix.h>
4 #include <gsl/gsl_odeiv.h>
7 func (double t, const double y[], double f[],
10 double mu = *(double *)params;
12 f[1] = -y[0] - mu*y[1]*(y[0]*y[0] - 1);
17 jac (double t, const double y[], double *dfdy,
18 double dfdt[], void *params)
20 double mu = *(double *)params;
21 gsl_matrix_view dfdy_mat
22 = gsl_matrix_view_array (dfdy, 2, 2);
23 gsl_matrix * m = &dfdy_mat.matrix;
24 gsl_matrix_set (m, 0, 0, 0.0);
25 gsl_matrix_set (m, 0, 1, 1.0);
26 gsl_matrix_set (m, 1, 0, -2.0*mu*y[0]*y[1] - 1.0);
27 gsl_matrix_set (m, 1, 1, -mu*(y[0]*y[0] - 1.0));
36 const gsl_odeiv_step_type * T
37 = gsl_odeiv_step_rk8pd;
40 = gsl_odeiv_step_alloc (T, 2);
42 = gsl_odeiv_control_y_new (1e-6, 0.0);
44 = gsl_odeiv_evolve_alloc (2);
47 gsl_odeiv_system sys = {func, jac, 2, &mu};
49 double t = 0.0, t1 = 100.0;
51 double y[2] = { 1.0, 0.0 };
55 int status = gsl_odeiv_evolve_apply (e, c, s,
60 if (status != GSL_SUCCESS)
63 printf ("%.5e %.5e %.5e\n", t, y[0], y[1]);
66 gsl_odeiv_evolve_free (e);
67 gsl_odeiv_control_free (c);
68 gsl_odeiv_step_free (s);