'''
This file is part of PM4Py (More Info: https://pm4py.fit.fraunhofer.de).
PM4Py is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
PM4Py is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with PM4Py. If not, see <https://www.gnu.org/licenses/>.
'''
from pm4py.objects.transition_system import obj
[docs]def add_arc_from_to(name, fr, to, ts, data=None):
"""
Adds a transition from a state to another state in some transition system.
Assumes from and to are in the transition system!
Parameters
----------
name: name of the transition
fr: state from
to: state to
ts: transition system to use
data: data associated to the Transition System
Returns
-------
None
"""
tran = obj.TransitionSystem.Transition(name, fr, to, data)
ts.transitions.add(tran)
fr.outgoing.add(tran)
to.incoming.add(tran)
[docs]def remove_arc_from_to(name, fr, to, ts):
"""
Removes a transition with a specific name from a state to another state in some transition system.
Assumes from and to are in the transition system!
Parameters
----------
name: name of the transition
fr: state from
to: state to
ts: transition system to use
Returns
-------
None
"""
ts.transitions = [t for t in ts.transitions if t.name != name]
fr.outgoing = [t for t in fr.outgoing if t.name != name]
to.incoming = [t for t in to.incoming if t.name != name]
[docs]def remove_all_arcs_from_to(fr, to, ts):
"""
Removes all transitions from a state to another state in some transition system.
Assumes from and to are in the transition system!
Parameters
----------
fr: state from
to: state to
ts: transition system to use
Returns
-------
None
"""
names_transitions_to_delete = [t.name for t in ts.transitions if t in fr.outgoing and t in to.incoming]
ts.transitions = set([t for t in ts.transitions if t.name not in names_transitions_to_delete])
fr.outgoing = set([t for t in fr.outgoing if t.name not in names_transitions_to_delete])
to.incoming = set([t for t in to.incoming if t.name not in names_transitions_to_delete])
[docs]def transitive_reduction(ts):
"""
Computes the transitive reduction of an acyclic transition system.
Assumes the transition system in input to be acyclic.
Parameters
----------
ts: acyclic transition system to use
Returns
-------
None
"""
def check(this_state, this_child, this_done):
if this_child not in this_done:
child_children = [tr.to_state for tr in ts.transitions if tr in this_child.outgoing]
for child_child in child_children:
remove_all_arcs_from_to(this_state, child_child, ts)
check(this_state, child_child, this_done)
this_done.add(this_child)
for state in ts.states:
done = set()
children = [tr.to_state for tr in ts.transitions if tr in state.outgoing]
for child in children:
check(state, child, done)