gtsam/python/gtsam/examples/Pose2SLAMExample_g2o.py

98 lines
3.2 KiB
Python

"""
GTSAM Copyright 2010-2018, Georgia Tech Research Corporation,
Atlanta, Georgia 30332-0415
All Rights Reserved
Authors: Frank Dellaert, et al. (see THANKS for the full author list)
See LICENSE for the license information
A 2D Pose SLAM example that reads input from g2o, converts it to a factor graph
and does the optimization. Output is written on a file, in g2o format
"""
# pylint: disable=invalid-name, E1101
from __future__ import print_function
import argparse
import gtsam
import matplotlib.pyplot as plt
from gtsam.utils import plot
def main():
"""Main runner."""
parser = argparse.ArgumentParser(
description="A 2D Pose SLAM example that reads input from g2o, "
"converts it to a factor graph and does the optimization. "
"Output is written on a file, in g2o format")
parser.add_argument('-i', '--input', help='input file g2o format')
parser.add_argument(
'-o',
'--output',
help="the path to the output file with optimized graph")
parser.add_argument('-m',
'--maxiter',
type=int,
help="maximum number of iterations for optimizer")
parser.add_argument('-k',
'--kernel',
choices=['none', 'huber', 'tukey'],
default="none",
help="Type of kernel used")
parser.add_argument("-p",
"--plot",
action="store_true",
help="Flag to plot results")
args = parser.parse_args()
g2oFile = gtsam.findExampleDataFile("noisyToyGraph.txt") if args.input is None\
else args.input
maxIterations = 100 if args.maxiter is None else args.maxiter
is3D = False
graph, initial = gtsam.readG2o(g2oFile, is3D)
assert args.kernel == "none", "Supplied kernel type is not yet implemented"
# Add prior on the pose having index (key) = 0
priorModel = gtsam.noiseModel.Diagonal.Variances(gtsam.Point3(1e-6, 1e-6, 1e-8))
graph.add(gtsam.PriorFactorPose2(0, gtsam.Pose2(), priorModel))
params = gtsam.GaussNewtonParams()
params.setVerbosity("Termination")
params.setMaxIterations(maxIterations)
# parameters.setRelativeErrorTol(1e-5)
# Create the optimizer ...
optimizer = gtsam.GaussNewtonOptimizer(graph, initial, params)
# ... and optimize
result = optimizer.optimize()
print("Optimization complete")
print("initial error = ", graph.error(initial))
print("final error = ", graph.error(result))
if args.output is None:
print("\nFactor Graph:\n{}".format(graph))
print("\nInitial Estimate:\n{}".format(initial))
print("Final Result:\n{}".format(result))
else:
outputFile = args.output
print("Writing results to file: ", outputFile)
graphNoKernel, _ = gtsam.readG2o(g2oFile, is3D)
gtsam.writeG2o(graphNoKernel, result, outputFile)
print("Done!")
if args.plot:
resultPoses = gtsam.utilities.extractPose2(result)
for i in range(resultPoses.shape[0]):
plot.plot_pose2(1, gtsam.Pose2(resultPoses[i, :]))
plt.show()
if __name__ == "__main__":
main()