Spaces:
Running
Running
File size: 2,624 Bytes
e60e568 |
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 |
'''
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 statistics import mean
from enum import Enum
from pm4py.util import exec_utils
from typing import Optional, Dict, Any, Union
from pm4py.objects.petri_net.obj import PetriNet
class Parameters(Enum):
K = "k"
def apply(petri_net: PetriNet, parameters: Optional[Dict[Union[str, Parameters], Any]] = None) -> float:
"""
Gets simplicity from a Petri net
Vázquez-Barreiros, Borja, Manuel Mucientes, and Manuel Lama. "ProDiGen: Mining complete, precise and minimal
structure process models with a genetic algorithm." Information Sciences 294 (2015): 315-333.
Parameters
-----------
petri_net
Petri net
parameters
Possible parameters of the algorithm:
- K: defines the value to be substracted in the formula: the lower is the value,
the lower is the simplicity value. k is the baseline arc degree (that is subtracted from the others)
Returns
-----------
simplicity
Simplicity measure associated to the Petri net
"""
if parameters is None:
parameters = {}
# original model: we have plenty of choices there.
# one choice is about taking a model containing the most frequent variant,
# along with a short circuit between the final and the initial marking.
# in that case, the average arc degree of the "original model" is 2
# keep the default to 2
k = exec_utils.get_param_value(Parameters.K, parameters, 2)
# TODO: verify the real provenence of the approach before!
all_arc_degrees = []
for place in petri_net.places:
all_arc_degrees.append(len(place.in_arcs) + len(place.out_arcs))
for trans in petri_net.transitions:
all_arc_degrees.append(len(trans.in_arcs) + len(trans.out_arcs))
mean_degree = mean(all_arc_degrees) if all_arc_degrees else 0.0
simplicity = 1.0 / (1.0 + max(mean_degree - k, 0))
return simplicity
|