env/gtsam-4.1.1/python

README

Python Wrapper

This is the Python wrapper around the GTSAM C++ library. We use our custom wrap library to generate the bindings to the underlying C++ code.

For instructions on updating the version of the wrap library included in GTSAM to the latest version, please refer to the wrap README

Requirements

• If you want to build the GTSAM python library for a specific python version (eg 3.6), use the -DGTSAM_PYTHON_VERSION=3.6 option when running cmake otherwise the default interpreter will be used.
• If the interpreter is inside an environment (such as an anaconda environment or virtualenv environment), then the environment should be active while building GTSAM.
• This wrapper needs pyparsing(>=2.4.2), and numpy(>=1.11.0). These can be installed as follows:

  pip install -r <gtsam_folder>/python/requirements.txt

Install

• Run cmake with the GTSAM_BUILD_PYTHON cmake flag enabled to configure building the wrapper. The wrapped module will be built and copied to the directory <PROJECT_BINARY_DIR>/python. For example, if your local Python version is 3.6.10, then you should run: bash cmake .. -DGTSAM_BUILD_PYTHON=1 -DGTSAM_PYTHON_VERSION=3.6.10 If you do not have TBB installed, you should also provide the argument -DGTSAM_WITH_TBB=OFF. - Build GTSAM and the wrapper with make (or ninja if you use -GNinja). - To install, simply run make python-install (ninja python-install). - The same command can be used to install into a virtual environment if it is active. - NOTE: if you don't want GTSAM to install to a system directory such as /usr/local, pass -DCMAKE_INSTALL_PREFIX="./install" to cmake to install GTSAM to a subdirectory of the build directory. - You can also directly run make python-install without running make, and it will compile all the dependencies accordingly. ## Unit Tests The Python toolbox also has a small set of unit tests located in the test directory. To run them, use make python-test. ## Utils TODO ## Examples TODO ## Writing Your Own Scripts See the tests for examples. ### Some Important Notes: - Vector/Matrix: - GTSAM expects double-precision floating point vectors and matrices. Hence, you should pass numpy matrices with dtype=float, or float64, to avoid any conversion needed. - Also, GTSAM expects column-major matrices, unlike the default storage scheme in numpy. But this is only performance-related as pybind11 should translate them when needed. However, this will result a copy if your matrix is not in the expected type and storage order. ## Wrapping Custom GTSAM-based Project Please refer to the template project and the corresponding tutorial available here.