int main (void) { double mu = 10; gsl_odeiv2_system sys = { func, jac, 2, &mu }; gsl_odeiv2_driver *d = gsl_odeiv2_driver_alloc_y_new (&sys, gsl_odeiv2_step_rk4, 1e-3, 1e-8, 1e-8); double t = 0.0; double y[2] = { 1.0, 0.0 }; int i, s; for (i = 0; i < 100; i++) { s = gsl_odeiv2_driver_apply_fixed_step (d, &t, 1e-3, 1000, y); if (s != GSL_SUCCESS) { printf ("error: driver returned %d\n", s); break; } printf ("%.5e %.5e %.5e\n", t, y[0], y[1]); } gsl_odeiv2_driver_free (d); return s; }