ros-np-tools

A set of reusable functions and classes for reducing boilerplate ROS and numpy code.

In particular, can be useful for converting between ROS and numpy types, converting between different ROS types, and updating ros transforms.

This is a living library, so the signatures of existing functions will not be changed, but new functions and/or modules will be periodically added.

Installation

Ensure that a system-wide ros installation already exists. Then,

pip install -e .

For virtualenv/conda

If you're using virtualenv/conda for python, you should be okay as long as the following considerations are met:

• Your PYTHONPATH should contain /opt/ros/ros_dist/lib/python3/dist-packages, by default this is done when you call source /opt/ros/ros_dist/setup.bash, which should be in your .bashrc after installing ROS.
• Some python packages are not installed in /opt/ros/..., but rather /usr/lib/python3/dist-packages. To access these libraries in your virtual/conda env, you need to install them manually (since adding /usr/lib/python3/dist-packages to your PYTHONPATH doesn't work, nor should it). Most are installed automatically via the setup.py requirements, but unfortunately the version of PyKDL automatically installed via pip is the wrong one, so you must install a custom wheel as follows:
  • Install the custom wheel for your machine and python version from here. Download the .whl file and install with pip install .. Thanks to @otamachan for setting this up.

Usage

Each file is named based on the output of each of the functions it contains. For example, to convert from a 4x4 transform matrix to a Transform msg, you would call ros_np_tools.tf_msg.mat_to_tf_msg.