import networkx as nx
import numpy as np
from pm4py.algo.analysis.woflan.graphs import utility as helper
[docs]def apply(net, initial_marking, original_net=None):
"""
Method that computes a reachability graph as networkx object
:param net: Petri Net
:param initial_marking: Initial Marking of the Petri Net
:param original_net: Petri Net without short-circuited transition
:return: Networkx Graph that represents the reachability graph of the Petri Net
"""
initial_marking = helper.convert_marking(net, initial_marking, original_net)
firing_dict = helper.split_incidence_matrix(helper.compute_incidence_matrix(net), net)
req_dict = helper.compute_firing_requirement(net)
look_up_indices = {}
j = 0
reachability_graph = nx.MultiDiGraph()
reachability_graph.add_node(j, marking=initial_marking)
working_set = set()
working_set.add(j)
look_up_indices[np.array2string(initial_marking)] = j
j += 1
while len(working_set) > 0:
m = working_set.pop()
possible_markings = helper.enabled_markings(firing_dict, req_dict, reachability_graph.nodes[m]['marking'])
for marking in possible_markings:
if np.array2string(marking[0]) not in look_up_indices:
look_up_indices[np.array2string(marking[0])] = j
reachability_graph.add_node(j, marking=marking[0])
working_set.add(j)
reachability_graph.add_edge(m, j, transition=marking[1])
j += 1
else:
reachability_graph.add_edge(m, look_up_indices[np.array2string(marking[0])], transition=marking[1])
return reachability_graph