gtsam/cython/test/test_LocalizationExample.py

53 lines
2.0 KiB
Python

import unittest
from gtsam import *
from gtsam_utils import *
from math import *
import numpy as np
class TestLocalizationExample(unittest.TestCase):
def test_LocalizationExample(self):
# Create the graph (defined in pose2SLAM.h, derived from
# NonlinearFactorGraph)
graph = NonlinearFactorGraph()
# Add two odometry factors
# create a measurement for both factors (the same in this case)
odometry = Pose2(2.0, 0.0, 0.0)
odometryNoise = noiseModel_Diagonal.Sigmas(
np.array([0.2, 0.2, 0.1])) # 20cm std on x,y, 0.1 rad on theta
graph.add(BetweenFactorPose2(0, 1, odometry, odometryNoise))
graph.add(BetweenFactorPose2(1, 2, odometry, odometryNoise))
# Add three "GPS" measurements
# We use Pose2 Priors here with high variance on theta
groundTruth = Values()
groundTruth.insert(0, Pose2(0.0, 0.0, 0.0))
groundTruth.insert(1, Pose2(2.0, 0.0, 0.0))
groundTruth.insert(2, Pose2(4.0, 0.0, 0.0))
model = noiseModel_Diagonal.Sigmas(np.array([0.1, 0.1, 10.]))
for i in range(3):
graph.add(PriorFactorPose2(i, groundTruth.atPose2(i), model))
# Initialize to noisy points
initialEstimate = Values()
initialEstimate.insert(0, Pose2(0.5, 0.0, 0.2))
initialEstimate.insert(1, Pose2(2.3, 0.1, -0.2))
initialEstimate.insert(2, Pose2(4.1, 0.1, 0.1))
# Optimize using Levenberg-Marquardt optimization with an ordering from
# colamd
optimizer = LevenbergMarquardtOptimizer(graph, initialEstimate)
result = optimizer.optimizeSafely()
# Plot Covariance Ellipses
marginals = Marginals(graph, result)
P = [None] * result.size()
for i in range(0, result.size()):
pose_i = result.atPose2(i)
self.assertTrue(pose_i.equals(groundTruth.atPose2(i), 1e-4))
P[i] = marginals.marginalCovariance(i)
if __name__ == "__main__":
unittest.main()