def acyclic_net_variants(net,
initial_marking,
final_marking,
activity_key=xes_util.DEFAULT_NAME_KEY):
"""
Given an acyclic accepting Petri net, initial and final marking extracts a set of variants (in form of traces)
replayable on the net.
Warning: this function is based on a marking exploration. If the accepting Petri net contains loops, the method
will not work properly as it stops the search if a specific marking has already been encountered.
Parameters
----------
:param net: An acyclic workflow net
:param initial_marking: The initial marking of the net.
:param final_marking: The final marking of the net.
:param activity_key: activity key to use
Returns
-------
:return: variants: :class:`list` Set of variants - in the form of Trace objects - obtainable executing the net
"""
active = {(initial_marking, ())}
visited = set()
variants = set()
while active:
curr_marking, curr_partial_trace = active.pop()
curr_pair = (curr_marking, curr_partial_trace)
enabled_transitions = semantics.enabled_transitions(net, curr_marking)
for transition in enabled_transitions:
if transition.label is not None:
next_partial_trace = curr_partial_trace + (transition.label, )
else:
next_partial_trace = curr_partial_trace
next_marking = semantics.execute(transition, net, curr_marking)
next_pair = (next_marking, next_partial_trace)
if next_marking == final_marking:
variants.add(next_partial_trace)
else:
# If the next marking is not in visited, if the next marking+partial trace is different from the current one+partial trace
if next_pair not in visited and curr_pair != next_pair:
active.add(next_pair)
visited.add(curr_pair)
trace_variants = []
for variant in variants:
trace = Trace()
for activity_label in variant:
trace.append(Event({activity_key: activity_label}))
trace_variants.append(trace)
return trace_variants
def get_visible_transitions_eventually_enabled_by_marking(net, marking):
"""
Get visible transitions eventually enabled by marking (passing possibly through hidden transitions)
Parameters
----------
net
Petri net
marking
Current marking
"""
all_enabled_transitions = sorted(list(semantics.enabled_transitions(net, marking)),
key=lambda x: (str(x.name), id(x)))
initial_all_enabled_transitions_marking_dictio = {}
all_enabled_transitions_marking_dictio = {}
for trans in all_enabled_transitions:
all_enabled_transitions_marking_dictio[trans] = marking
initial_all_enabled_transitions_marking_dictio[trans] = marking
visible_transitions = set()
visited_transitions = set()
i = 0
while i < len(all_enabled_transitions):
t = all_enabled_transitions[i]
marking_copy = copy(all_enabled_transitions_marking_dictio[t])
if repr([t, marking_copy]) not in visited_transitions:
if t.label is not None:
visible_transitions.add(t)
else:
if semantics.is_enabled(t, net, marking_copy):
new_marking = semantics.execute(t, net, marking_copy)
new_enabled_transitions = sorted(list(semantics.enabled_transitions(net, new_marking)),
key=lambda x: (str(x.name), id(x)))
for t2 in new_enabled_transitions:
all_enabled_transitions.append(t2)
all_enabled_transitions_marking_dictio[t2] = new_marking
visited_transitions.add(repr([t, marking_copy]))
i = i + 1
return visible_transitions
def apply_playout(net,
initial_marking,
no_traces=100,
max_trace_length=100,
case_id_key=xes_constants.DEFAULT_TRACEID_KEY,
activity_key=xes_constants.DEFAULT_NAME_KEY,
timestamp_key=xes_constants.DEFAULT_TIMESTAMP_KEY,
final_marking=None,
smap=None,
log=None,
return_visited_elements=False):
"""
Do the playout of a Petrinet generating a log
Parameters
----------
net
Petri net to play-out
initial_marking
Initial marking of the Petri net
no_traces
Number of traces to generate
max_trace_length
Maximum number of events per trace (do break)
case_id_key
Trace attribute that is the case ID
activity_key
Event attribute that corresponds to the activity
timestamp_key
Event attribute that corresponds to the timestamp
final_marking
If provided, the final marking of the Petri net
smap
Stochastic map
log
Log
"""
if final_marking is None:
# infer the final marking from the net
final_marking = final_marking_discovery.discover_final_marking(net)
if smap is None:
if log is None:
raise Exception(
"please provide at least one between stochastic map and log")
smap = replay.get_map_from_log_and_net(log,
net,
initial_marking,
final_marking,
parameters={
Parameters.ACTIVITY_KEY:
activity_key,
Parameters.TIMESTAMP_KEY:
timestamp_key
})
# assigns to each event an increased timestamp from 1970
curr_timestamp = 10000000
all_visited_elements = []
for i in range(no_traces):
visited_elements = []
visible_transitions_visited = []
marking = copy(initial_marking)
while len(visible_transitions_visited) < max_trace_length:
visited_elements.append(marking)
if not semantics.enabled_transitions(
net, marking): # supports nets with possible deadlocks
break
all_enabled_trans = semantics.enabled_transitions(net, marking)
if final_marking is not None and marking == final_marking:
en_t_list = list(all_enabled_trans.union({None}))
else:
en_t_list = list(all_enabled_trans)
trans = stochastic_utils.pick_transition(en_t_list, smap)
if trans is None:
break
visited_elements.append(trans)
if trans.label is not None:
visible_transitions_visited.append(trans)
marking = semantics.execute(trans, net, marking)
all_visited_elements.append(tuple(visited_elements))
if return_visited_elements:
return all_visited_elements
log = log_instance.EventLog()
for index, visited_elements in enumerate(all_visited_elements):
trace = log_instance.Trace()
trace.attributes[case_id_key] = str(index)
for element in visited_elements:
if type(element
) is PetriNet.Transition and element.label is not None:
event = log_instance.Event()
event[activity_key] = element.label
event[timestamp_key] = datetime.datetime.fromtimestamp(
curr_timestamp)
trace.append(event)
# increases by 1 second
curr_timestamp += 1
log.append(trace)
return log