def test_backward_euler(): func = lambda t, y: 2*t ode = ode_solver.ODE_solver(func, 0.8, [1, 2], 0.2) t, y = ode.backward_euler() assert np.allclose(t, [1, 1.2, 1.4, 1.5999999999999999, 1.7999999999999998, 1.9999999999999998, 2]) assert np.allclose(y, [0.8, 1.28, 1.8399999999999999, 2.48, 3.2, 4.0, 4.88])
def test_BDF_negylist(): func = lambda t, y: 2*np.array(y)+np.array([t, t]) obj = ode_solver.ODE_solver(func, [-1, 1], [10., 10.1], 0.1, False) t, y = obj.BDF() y0 = y[0] y1 = y[1] assert np.allclose(t, [10, 10.1]) assert np.allclose(y0, [0.0, 1]) assert np.allclose(y1, [1.1123736, 2.33377809])
def test_backward_euler_negylist(): func = lambda t, y: 2*np.array(y)+np.array([t, t]) obj = ode_solver.ODE_solver(func, [-1, 1], [10., 10.1], 0.1, False) t, y = obj.backward_euler() y0 = y[0] y1 = y[1] assert np.allclose(t, [10, 10.1]) assert np.allclose(y0, [0.0, 1]) assert np.allclose(y1, [1.26249987, 2.51249985])
def __init__(self,
reaction_system,
initial_abundances,
temperature,
t_span,
dt=0.01):
self.reaction_system = reaction_system
self.temperature = temperature
self.t_span = t_span
self.times = [self.t_span[0]]
self.abundances = [initial_abundances]
try:
dt = float(dt)
except:
raise ValueError("Could not convert dt=%s to float" % dt)
self.dt = dt
self._validate_arguments()
self.ode_integrator = ode_solver.ODE_solver(self.diff_func,
initial_abundances, t_span,
self.dt, False)
def test_backward_euler_step_failure(): func = lambda t, y: 2*y+t obj = ode_solver.ODE_solver(func, 1., [10., 11.], 1) assert obj.backward_euler_step() == "Failure"
def test_BDF_negy(): func = lambda t, y: 2*y+t obj = ode_solver.ODE_solver(func, -1, [10, 10.02], 0.01, False) t, y = obj.BDF() assert np.allclose(t, [10, 10.01, 10.02]) assert np.allclose(y, [0.0, 0.10105761562779661, 0.20425719527441025])
def test_backward_euler_negy(): func = lambda t, y: 2*y+t obj = ode_solver.ODE_solver(func, -1, [10, 10.02], 0.01, False) t, y = obj.backward_euler() assert np.allclose(t, [10, 10.01, 10.02]) assert np.allclose(y, [0.0, 0.10214284080000001, 0.20647226983790093])
def test_rk45(): func = lambda t, y: 2*t ode = ode_solver.ODE_solver(func, 0.8, [1, 2], 0.2) t, y = ode.rk45() assert np.allclose(t, [1, 1.2, 2.0]) assert np.allclose(y, [0.8, 1.2400000000000002, 3.8000000000000007])