gtsam/python/gtsam/tests/test_DiscreteBayesTree.py

80 lines
2.7 KiB
Python

"""
GTSAM Copyright 2010-2021, Georgia Tech Research Corporation,
Atlanta, Georgia 30332-0415
All Rights Reserved
See LICENSE for the license information
Unit tests for Discrete Bayes trees.
Author: Frank Dellaert
"""
# pylint: disable=no-name-in-module, invalid-name
import unittest
from gtsam import (DiscreteBayesNet, DiscreteBayesTreeClique,
DiscreteConditional, DiscreteFactorGraph, Ordering)
from gtsam.utils.test_case import GtsamTestCase
class TestDiscreteBayesNet(GtsamTestCase):
"""Tests for Discrete Bayes Nets."""
def test_elimination(self):
"""Test Multifrontal elimination."""
# Define DiscreteKey pairs.
keys = [(j, 2) for j in range(15)]
# Create thin-tree Bayesnet.
bayesNet = DiscreteBayesNet()
bayesNet.add(keys[0], [keys[8], keys[12]], "2/3 1/4 3/2 4/1")
bayesNet.add(keys[1], [keys[8], keys[12]], "4/1 2/3 3/2 1/4")
bayesNet.add(keys[2], [keys[9], keys[12]], "1/4 8/2 2/3 4/1")
bayesNet.add(keys[3], [keys[9], keys[12]], "1/4 2/3 3/2 4/1")
bayesNet.add(keys[4], [keys[10], keys[13]], "2/3 1/4 3/2 4/1")
bayesNet.add(keys[5], [keys[10], keys[13]], "4/1 2/3 3/2 1/4")
bayesNet.add(keys[6], [keys[11], keys[13]], "1/4 3/2 2/3 4/1")
bayesNet.add(keys[7], [keys[11], keys[13]], "1/4 2/3 3/2 4/1")
bayesNet.add(keys[8], [keys[12], keys[14]], "T 1/4 3/2 4/1")
bayesNet.add(keys[9], [keys[12], keys[14]], "4/1 2/3 F 1/4")
bayesNet.add(keys[10], [keys[13], keys[14]], "1/4 3/2 2/3 4/1")
bayesNet.add(keys[11], [keys[13], keys[14]], "1/4 2/3 3/2 4/1")
bayesNet.add(keys[12], [keys[14]], "3/1 3/1")
bayesNet.add(keys[13], [keys[14]], "1/3 3/1")
bayesNet.add(keys[14], "1/3")
# Create a factor graph out of the Bayes net.
factorGraph = DiscreteFactorGraph(bayesNet)
# Create a BayesTree out of the factor graph.
ordering = Ordering()
for j in range(15):
ordering.push_back(j)
bayesTree = factorGraph.eliminateMultifrontal(ordering)
# Uncomment these for visualization:
# print(bayesTree)
# for key in range(15):
# bayesTree[key].printSignature()
# bayesTree.saveGraph("test_DiscreteBayesTree.dot")
self.assertFalse(bayesTree.empty())
self.assertEqual(12, bayesTree.size())
# The root is P( 8 12 14), we can retrieve it by key:
root = bayesTree[8]
self.assertIsInstance(root, DiscreteBayesTreeClique)
self.assertTrue(root.isRoot())
self.assertIsInstance(root.conditional(), DiscreteConditional)
if __name__ == "__main__":
unittest.main()