def test_line_release_with_big_timestep():
"""
a line release: where the timestep spans before to after the release time
"""
release_time = datetime(2012, 1, 1)
end_time = release_time + timedelta(seconds=100)
time_step = timedelta(seconds=300)
start_pos = np.array((0., 0., 0.))
end_pos = np.array((1.0, 2.0, 0.))
sp = PointLineSource(num_elements=10,
start_position=start_pos,
release_time=release_time,
end_position=end_pos,
end_release_time=end_time)
num = sp.num_elements_to_release(release_time - timedelta(seconds=100),
time_step.total_seconds())
assert num == sp.num_elements
data_arrays = mock_append_data_arrays(arr_types, num)
sp.set_newparticle_values(num, release_time - timedelta(seconds=100),
time_step.total_seconds(), data_arrays)
# all axes should release particles with same, evenly spaced delta_position
for ix in range(3):
assert np.allclose(data_arrays['positions'][:, ix],
np.linspace(start_pos[ix], end_pos[ix], sp.num_elements))
def test_line_release_with_one_element():
"""
one element with a line release
-- doesn't really make sense, but it shouldn't crash
"""
release_time = datetime(2012, 1, 1)
end_time = release_time + timedelta(seconds=100)
time_step = timedelta(seconds=10)
start_pos = np.array((0., 0., 0.))
end_pos = np.array((1.0, 2.0, 0.))
sp = PointLineSource(num_elements=1,
start_position=start_pos,
release_time=release_time,
end_position=end_pos,
end_release_time=end_time)
num = sp.num_elements_to_release(release_time, time_step.total_seconds())
data_arrays = mock_append_data_arrays(arr_types, num)
assert num == 1
sp.set_newparticle_values(num, release_time, time_step.total_seconds(),
data_arrays)
assert sp.num_released == 1
assert np.array_equal(data_arrays['positions'], [start_pos])
def test_cont_line_release_single_elem_over_multiple_timesteps(self,
start_position, end_position):
"""
testing a release that is releasing while moving over time
- less than one elements is released per step. A single element is
released over multiple time steps.
Test it's right for the full release
"""
sp = PointLineSource(num_elements=10,
start_position=start_position,
release_time=self.release_time,
end_position=end_position,
end_release_time=self.release_time + timedelta(minutes=50))
# start before release
time = self.release_time - timedelta(minutes=2)
delta_t = timedelta(minutes=2)
timestep = delta_t.total_seconds()
data_arrays = {}
# end after release
while time < sp.end_release_time + delta_t:
"""
keep releasing particles - no need to use self.release_and_assert
since computing expected_number_of_particles_released is cumbersome
Also, other tests verify that expected number of particles are
being released - keep this easy to understand and follow
"""
num = sp.num_elements_to_release(time, timestep)
data_arrays = mock_append_data_arrays(arr_types, num, data_arrays)
sp.set_newparticle_values(num, time, timestep, data_arrays)
time += delta_t
assert data_arrays['positions'].shape == (sp.num_elements, 3)
assert np.array_equal(data_arrays['positions'][0], sp.start_position)
assert np.array_equal(data_arrays['positions'][-1], sp.end_position)
# the delta position is a constant and is given by
# (sp.end_position-sp.start_position)/(sp.num_elements-1)
delta_p = (sp.end_position - sp.start_position) / (sp.num_elements - 1)
assert np.all(delta_p == sp.delta_pos)
assert np.allclose(delta_p, np.diff(data_arrays['positions'], axis=0),
0, 1e-10)
def test_single_line(num_elements):
"""
various numbers of elemenets over ten time steps, so release
is less than one, one and more than one per time step.
"""
print 'using num_elements:', num_elements
release_time = datetime(2012, 1, 1)
end_time = release_time + timedelta(seconds=100)
time_step = timedelta(seconds=10)
start_pos = np.array((0., 0., 0.))
end_pos = np.array((1.0, 2.0, 0.))
sp = PointLineSource(num_elements=num_elements,
start_position=start_pos,
release_time=release_time,
end_position=end_pos,
end_release_time=end_time)
time = release_time
data_arrays = {}
while time <= end_time + time_step * 2:
#data = sp.release_elements(time, time_step.total_seconds())
num = sp.num_elements_to_release(time, time_step.total_seconds())
data_arrays = mock_append_data_arrays(arr_types, num, data_arrays)
if num > 0:
sp.set_newparticle_values(num, time, time_step.total_seconds(),
data_arrays)
time += time_step
assert len(data_arrays['positions']) == num_elements
assert np.allclose(data_arrays['positions'][0], start_pos)
assert np.allclose(data_arrays['positions'][-1], end_pos)
# all axes should release particles with same, evenly spaced delta_position
for ix in range(3):
assert np.allclose(data_arrays['positions'][:, ix],
np.linspace(start_pos[ix], end_pos[ix], num_elements))