gtsam/cython/gtsam/tests/test_GaussianFactorGraph.py

93 lines
2.9 KiB
Python

"""
GTSAM Copyright 2010-2019, Georgia Tech Research Corporation,
Atlanta, Georgia 30332-0415
All Rights Reserved
See LICENSE for the license information
Unit tests for Linear Factor Graphs.
Author: Frank Dellaert & Gerry Chen
"""
# pylint: disable=invalid-name, no-name-in-module, no-member
from __future__ import print_function
import unittest
import gtsam
import numpy as np
from gtsam import symbol_shorthand_X as X
from gtsam.utils.test_case import GtsamTestCase
def create_graph():
"""Create a basic linear factor graph for testing"""
graph = gtsam.GaussianFactorGraph()
x0 = X(0)
x1 = X(1)
x2 = X(2)
BETWEEN_NOISE = gtsam.noiseModel_Diagonal.Sigmas(np.ones(1))
PRIOR_NOISE = gtsam.noiseModel_Diagonal.Sigmas(np.ones(1))
graph.add(x1, np.eye(1), x0, -np.eye(1), np.ones(1), BETWEEN_NOISE)
graph.add(x2, np.eye(1), x1, -np.eye(1), 2*np.ones(1), BETWEEN_NOISE)
graph.add(x0, np.eye(1), np.zeros(1), PRIOR_NOISE)
return graph, (x0, x1, x2)
class TestGaussianFactorGraph(GtsamTestCase):
"""Tests for Gaussian Factor Graphs."""
def test_fg(self):
"""Test solving a linear factor graph"""
graph, X = create_graph()
result = graph.optimize()
EXPECTEDX = [0, 1, 3]
# check solutions
self.assertAlmostEqual(EXPECTEDX[0], result.at(X[0]), delta=1e-8)
self.assertAlmostEqual(EXPECTEDX[1], result.at(X[1]), delta=1e-8)
self.assertAlmostEqual(EXPECTEDX[2], result.at(X[2]), delta=1e-8)
def test_convertNonlinear(self):
"""Test converting a linear factor graph to a nonlinear one"""
graph, X = create_graph()
EXPECTEDM = [1, 2, 3]
# create nonlinear factor graph for marginalization
nfg = gtsam.LinearContainerFactor.ConvertLinearGraph(graph)
optimizer = gtsam.LevenbergMarquardtOptimizer(nfg, gtsam.Values())
nlresult = optimizer.optimizeSafely()
# marginalize
marginals = gtsam.Marginals(nfg, nlresult)
m = [marginals.marginalCovariance(x) for x in X]
# check linear marginalizations
self.assertAlmostEqual(EXPECTEDM[0], m[0], delta=1e-8)
self.assertAlmostEqual(EXPECTEDM[1], m[1], delta=1e-8)
self.assertAlmostEqual(EXPECTEDM[2], m[2], delta=1e-8)
def test_linearMarginalization(self):
"""Marginalize a linear factor graph"""
graph, X = create_graph()
result = graph.optimize()
EXPECTEDM = [1, 2, 3]
# linear factor graph marginalize
marginals = gtsam.Marginals(graph, result)
m = [marginals.marginalCovariance(x) for x in X]
# check linear marginalizations
self.assertAlmostEqual(EXPECTEDM[0], m[0], delta=1e-8)
self.assertAlmostEqual(EXPECTEDM[1], m[1], delta=1e-8)
self.assertAlmostEqual(EXPECTEDM[2], m[2], delta=1e-8)
if __name__ == '__main__':
unittest.main()