Source code for pm4py.evaluation.soundness.woflan.place_invariants.utility

```'''

PM4Py is free software: you can redistribute it and/or modify
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/>.
'''
import numpy as np

[docs]def removearray(L, arr):
"""
Remove an array from a given list and return the list with the removed element.
:param L: list object
:param arr: array that has to be removed
:return: list object without array
"""
ind = 0
size = len(L)
while ind != size and not np.array_equal(L[ind], arr):
ind += 1
if ind != size:
L.pop(ind)
else:

[docs]def transform_basis(basis, style=None):
"""
We construct a (I)LP to transform our basis into a set of vectors by using linear combination to fit certain styles/
properties
:param basis: list of p-invariants. Commonly computed by the method 'compute_place_invariants' in
place_invariants.py
:param style: String that is used to construct certain constraints
At the moment, 'uniform' (all weights have value 0 or 1), and 'weighted' (all weights are >=0) are supported
:return: List of p-invariants that fits the style
"""
import pulp

if style==None:
style='weighted'

# First, we want to check if a vector of a basis only contains non-positve entries. If so, then we multiply the
# vector -1.
modified_base = []
for vector in basis:
all_non_positiv = True
for entry in vector:
if entry > 0:
all_non_positiv = False
if all_non_positiv:
modified_base.append(-1 * vector)
else:
modified_base.append(vector)
#For uniform variants, it is necessary that the weight for a place is either 0 or 1. We collect the variants for
#which this condition does not hold. We also collect the variants for the weighted invariants the entry is <0.
to_modify = []
for vector in modified_base:
for entry in vector:
if ((entry < 0 or entry > 1) and style=='uniform') or ( entry < 0 and style=='weighted'):
to_modify.append(vector)
break
# if we have nothing to modify, we are done
if len(to_modify) > 0:
for vector in to_modify:
removearray(modified_base, vector)
set_B = range(0, len(modified_base))
prob = pulp.LpProblem("linear_combination", pulp.LpMinimize)
X = pulp.LpVariable.dicts("x", set_B, cat='Integer')
y = pulp.LpVariable("y", cat='Integer', lowBound=1)
prob += pulp.lpSum(X[i] for i in set_B)
if style=='uniform':
# variables for uniform. Therefore, the resulting weight can either be 0 or 1
z = pulp.LpVariable.dicts("z", range(0, len(vector)), lowBound=0, upBound=1, cat='Integer')
for i in range(len(vector)):
prob += pulp.lpSum(X[j]*modified_base[j][i] for j in range(len(modified_base)))+y*vector[i]== z[i]
elif style=='weighted':
for i in range(len(vector)):
prob += pulp.lpSum(X[j]*modified_base[j][i] for j in range(len(modified_base)))+y*vector[i] >= 0
prob.solve()
new_vector = np.zeros(len(vector))
if style=='weighted':
for i in range(len(new_vector)):
new_vector[i] = y.varValue * vector[i]
for j in range(len(modified_base)):
new_vector[i] = new_vector[i] + modified_base[j][i] * X[j].varValue
elif style=='uniform':
for i in range(len(new_vector)):
new_vector[i] = z[i].varValue
modified_base.append(new_vector)
return modified_base

[docs]def compute_uncovered_places(invariants, net):
"""
Compute a list of uncovered places for invariants of a given Petri Net. Note that there exists a separate algorithm
for s-components
:param invariants: list of invariants. Each invariants is a numpy-Array representation
:param net: Petri Net object of PM4Py
:return: List of uncovered place over all invariants
"""
place_list=list(net.places)
unncovered_list=place_list.copy()
for invariant in invariants:
for index, value in enumerate(invariant):
if value != 0:
if place_list[index] in unncovered_list:
unncovered_list.remove(place_list[index])
return unncovered_list
```