def test_build_states_invalid_buffer_capacity():
"""
Test to ensure that the build_states function raises an error if the buffer
capacity is less than 1
"""
with pytest.raises(ValueError):
build_states(
threshold=None,
system_capacity=None,
buffer_capacity=0,
)
def test_visualise_markov_chain(
num_of_servers, threshold, system_capacity, buffer_capacity
):
"""
Test that checks if a neworkx MultiDiGraph object is returned and that the set
of all nodes used is the same se as the set of all states that the build_states
function returns.
"""
all_states = build_states(
threshold=threshold,
system_capacity=system_capacity,
buffer_capacity=buffer_capacity,
)
set_of_all_states = set(all_states)
markov_chain_plot = visualise_markov_chain(
num_of_servers=num_of_servers,
threshold=threshold,
system_capacity=system_capacity,
buffer_capacity=buffer_capacity,
)
set_of_nodes = set(markov_chain_plot.nodes)
assert isinstance(markov_chain_plot, nx.classes.multidigraph.DiGraph)
assert set_of_all_states == set_of_nodes
plt.close() # TODO Investigate if it's possible to remove this line
def test_get_state_probabilities_array():
"""
Test to ensure that the sum of elements of the pi array equate to 1
"""
all_states = build_states(
threshold=3,
system_capacity=5,
buffer_capacity=4,
)
transition_matrix = get_transition_matrix(
lambda_2=0.1,
lambda_1=0.2,
mu=0.2,
num_of_servers=3,
threshold=3,
system_capacity=5,
buffer_capacity=4,
)
pi = get_steady_state_algebraically(
Q=transition_matrix, algebraic_function=np.linalg.solve
)
pi_array = get_markov_state_probabilities(
pi=pi, all_states=all_states, output=np.ndarray
)
assert round(np.nansum(pi_array), NUMBER_OF_DIGITS_TO_ROUND) == 1
def test_build_states(threshold, system_capacity, buffer_capacity):
"""
Test to ensure that the build_states function returns the correct number of
states, for different integer values of the threshold, system and buffer capacities
"""
states = build_states(
threshold=threshold,
system_capacity=system_capacity,
buffer_capacity=buffer_capacity,
)
if threshold > system_capacity:
assert len(states) == system_capacity + 1 # +2
else:
states_after_threshold = system_capacity - threshold + 1
size_of_s2 = states_after_threshold if states_after_threshold >= 0 else 0
all_states_size = size_of_s2 * (buffer_capacity + 1) + threshold
assert len(states) == all_states_size
def test_get_mean_number_of_individuals_examples():
"""
Some examples to ensure that the correct mean number of individuals are output
"""
all_states = build_states(threshold=4, system_capacity=20, buffer_capacity=20)
transition_matrix = get_transition_matrix(
lambda_2=0.2,
lambda_1=0.2,
mu=0.2,
num_of_servers=3,
threshold=4,
system_capacity=20,
buffer_capacity=20,
)
pi = get_steady_state_algebraically(
Q=transition_matrix, algebraic_function=np.linalg.solve
)
assert (
round(
get_mean_number_of_individuals_in_system(pi=pi, states=all_states),
NUMBER_OF_DIGITS_TO_ROUND,
)
== 2.88827497
)
assert (
round(
get_mean_number_of_individuals_in_service_area(pi=pi, states=all_states),
NUMBER_OF_DIGITS_TO_ROUND,
)
== 2.44439504
)
assert (
round(
get_mean_number_of_individuals_in_buffer_center(pi=pi, states=all_states),
NUMBER_OF_DIGITS_TO_ROUND,
)
== 0.44387993
)