# The `SparseTriangularMatrix` class represents a matrix with sparse triangular structure and provides
# methods for incrementing counts, getting support for items, setting support values, and removing
# infrequent entries based on a minimum support threshold.
#
# **Importing this algorithm into a python program**
#
# from PAMI.subgraphMining.basic import gspan as alg
#
# obj = alg.GSpan(iFile, minSupport)
#
# obj.mine()
#
# obj.run()
#
# frequentGraphs = obj.getFrequentSubgraphs()
#
# memUSS = obj.getMemoryUSS()
#
# obj.save(oFile)
#
# print("Total Memory in USS:", memUSS)
#
# memRSS = obj.getMemoryRSS()
#
# print("Total Memory in RSS", memRSS)
#
# run = obj.getRuntime()
#
# print("Total ExecutionTime in seconds:", run)
#
__copyright__ = """
Copyright (C) 2021 Rage Uday Kiran
This program 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.
This program 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 this program. If not, see <https://www.gnu.org/licenses/>.
"""
[docs]
class SparseTriangularMatrix:
def __init__(self):
self.matrix = {}
def __str__(self):
temp = []
for key in sorted(self.matrix.keys()):
subkeys = self.matrix[key]
subkeyStr = " ".join(f"{subkey}:{count}" for subkey, count in subkeys.items())
temp.append(f"{key}: {subkeyStr}\n")
return "".join(temp)
[docs]
def incrementCount(self, i, j):
if i < j:
key, subkey = i, j
else:
key, subkey = j, i
if key not in self.matrix:
self.matrix[key] = {subkey: 1}
else:
if subkey not in self.matrix[key]:
self.matrix[key][subkey] = 1
else:
self.matrix[key][subkey] += 1
[docs]
def getSupportForItems(self, i, j):
smaller, larger = min(i, j), max(i, j)
return self.matrix.get(smaller, {}).get(larger, 0)
[docs]
def setSupport(self, i, j, support):
smaller, larger = min(i, j), max(i, j)
if smaller not in self.matrix:
self.matrix[smaller] = {larger: support}
else:
self.matrix[smaller][larger] = support
[docs]
def removeInfrequentEntriesFromMatrix(self, minsup):
for key in list(self.matrix.keys()):
for subkey, value in list(self.matrix[key].items()):
if value < minsup:
del self.matrix[key][subkey]
if not self.matrix[key]:
del self.matrix[key]