Python utilities for estimating and transforming rigid body motion.
Project description
rigid-body-motion
Python utilities for estimating and transforming rigid body motion.
Documentation: https://rigid-body-motion.readthedocs.io
Overview
This package provides a high-level interface for transforming arrays describing motion of rigid bodies between different coordinate systems and reference frames. The core of the reference frame handling is a fast re-implementation of ROS’s tf2 library using numpy and numpy-quaternion. The package also provides first-class support for xarray data types.
Installation
rigid-body-motion can be installed via pip:
$ pip install rigid-body-motion
or via conda:
$ conda install -c phausamann -c conda-forge rigid-body-motion
Examples
Transform numpy arrays between coordinate systems:
import numpy as np
import rigid_body_motion as rbm
arr_cart = np.ones((10, 2))
arr_polar = rbm.transform_coordinates(arr_cart, outof="cartesian", into="polar")
Transform numpy arrays across a tree of reference frames:
import numpy as np
import rigid_body_motion as rbm
rbm.register_frame("world")
rbm.register_frame("child", parent="world", translation=(1., 0., 0.))
rbm.register_frame("child2", parent="world", translation=(-1., 0., 0.))
arr_child = np.ones((10, 3))
arr_child2 = rbm.transform_points(arr_child, outof="child", into="child2")
Credits
This package was created with Cookiecutter and the audreyr/cookiecutter-pypackage project template.
History
0.7.0 (May 19th, 2021)
New features
New from_euler_angles utility method.
Bug fixes & improvements
Importing ROS interface classes will not fail silently anymore and instead show the traceback of the import error.
0.6.0 (May 17th, 2021)
Breaking changes
Example data is now fetched via the pooch library and no longer a part of the package itself.
New features
New io module for import/export methods.
New ros.RosbagWriter class for writing rosbag files.
0.5.0 (March 16th, 2021)
Breaking changes
Top-level reference frame transform and lookup methods now all accept a return_timestamps argument that is False by default. Previously, methods would return timestamps only if the result of the transformation was timestamped. This does not affect the xarray interface.
lookup_transform now returns the correct transformation from the base frame to the target frame (instead of the other way around).
ReferenceFrame.get_transformation is deprecated and replaced by ReferenceFrame.lookup_transform.
New features
New plot module with plotting methods for static reference frames and arrays of points, quaternions and vectors.
New lookup_pose method that calculates the pose of a frame wrt another.
Bug fixes & improvements
Fixed "reference_frame" attribute incorrectly set by transform_vectors.
0.4.1 (February 18th, 2021)
Bug fixes & improvements
Fixed transform_coordinates failing when spatial dimension is first axis of array.
Fixed transform_linear_velocity and transform_angular_velocity failing when reference frame or moving frame is transformed across only static transforms.
Added allow_static parameter to lookup_twist, lookup_angular_velocity and lookup_linear_velocity to return zero velocity and no timestamps across only static transforms.
0.4.0 (February 11th, 2021)
New features
New lookup_linear_velocity and lookup_angular_velocity top-level methods.
New render_tree top-level method for printing out a graphical representation of a reference frame tree.
lookup_twist now accepts a mode parameter to specify the mode for angular velocity calculation.
Bug fixes & improvements
Fixed a bug where estimated angular velocity was all NaN when orientation contained NaNs.
0.3.0 (December 8th, 2020)
New features
Reference frames with timestamps now accept the discrete parameter, allowing for transformations to be fixed from their timestamp into the future.
rbm accessor for DataArrays implementing qinterp and qinv methods.
New best_fit_rotation and qinterp top-level methods.
Bug fixes & improvements
Refactor of internal timestamp matching mechanism defining a clear priority for target timestamps. This can result in slight changes of timestamps and arrays returned by transformations but will generally produce more accurate results.
Added mode and outlier_thresh arguments to estimate_angular_velocity.
Fixed issues with iterative_closest_point.
0.2.0 (October 22nd, 2020)
New features
New estimate_linear_velocity and estimate_angular_velocity top-level methods.
New qmul top-level method for multiplying quaternions.
0.1.2 (October 7th, 2020)
Improvements
Use SQUAD instead of linear interpolation for quaternions.
0.1.1 (September 17th, 2020)
Bug fixes
Fix transformations failing for DataArrays with non-numeric coords.
0.1.0 (September 17th, 2020)
First release
Project details
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