def check_velocity_distribution(self, vel, minmax, n_bins, error_tol, kT):
"""check the recorded particle distributions in vel againsta histogram with n_bins bins. Drop velocities outside minmax. Check individual histogram bins up to an accuracy of error_tol agaisnt the analytical result for kT."""
for i in range(3):
hist = np.histogram(vel[:, i],
range=(-minmax, minmax),
bins=n_bins,
normed=False)
data = hist[0] / float(vel.shape[0])
bins = hist[1]
for j in range(n_bins):
found = data[j]
expected = single_component_maxwell(bins[j], bins[j + 1], kT)
self.assertLessEqual(abs(found - expected), error_tol)
def test_velocity_distribution(self):
self.prepare()
self.system.integrator.run(20)
N = len(self.system.part)
loops = 250
v_stored = np.zeros((N * loops, 3))
for i in range(loops):
self.system.integrator.run(6)
v_stored[i * N:(i + 1) * N, :] = self.system.part[:].v
minmax = 5
n_bins = 7
error_tol = 0.01
for i in range(3):
hist = np.histogram(v_stored[:, i], range=(-minmax, minmax),
bins=n_bins, normed=False)
data = hist[0] / float(v_stored.shape[0])
bins = hist[1]
for j in range(n_bins):
found = data[j]
expected = single_component_maxwell(bins[j], bins[j + 1], KT)
self.assertLessEqual(abs(found - expected), error_tol)
def test_00_verify_single_component_maxwell(self):
"""Verifies the normalization of the analytical expression."""
self.assertLessEqual(abs(single_component_maxwell(-10, 10, 4.) - 1.),
1E-4)
def test_00_verify_single_component_maxwell(self):
"""Verifies the normalization of the analytical expression."""
self.assertAlmostEqual(single_component_maxwell(-10, 10, 4.),
1.,
delta=1E-4)
