WRAP

The wrap library wraps the GTSAM library into a Python library or MATLAB toolbox. It was designed to be more general than just wrapping GTSAM. For notes on creating a wrap interface, see gtsam.h for what features can be wrapped into a toolbox, as well as the current state of the toolbox for GTSAM.

Prerequisites

Pybind11 and pyparsing

1. This library uses pybind11, which is included as a subdirectory in GTSAM.
2. The interface_parser.py in this library uses pyparsing to parse the interface file gtsam.h. Please install it first in your current Python environment before attempting the build.

python3 -m pip install pyparsing

Getting Started

Clone this repository to your local machine and perform the standard CMake install:

mkdir build && cd build
cmake ..
make install # use sudo if needed

Using wrap in your project is straightforward from here. In your CMakeLists.txt file, you just need to add the following:

find_package(gtwrap)

pybind_wrap(${PROJECT_NAME}_py # target
            ${PROJECT_SOURCE_DIR}/cpp/${PROJECT_NAME}.h # interface header file
            "${PROJECT_NAME}.cpp" # the generated cpp
            "${PROJECT_NAME}" # module_name
            "${PROJECT_MODULE_NAME}" # top namespace in the cpp file e.g. gtsam
            "${ignore}" # ignore classes
            ${PROJECT_BINARY_DIR}/${PROJECT_NAME}.tpl # the wrapping template file
            ${PROJECT_NAME} # libs
            "${PROJECT_NAME}" # dependencies
            ON # use boost
            )

For more information, please follow our tutorial.

Documentation

Documentation for wrapping C++ code can be found here.

Python Wrapper

WARNING: On macOS, you have to statically build GTSAM to use the wrapper.

1. Set GTSAM_BUILD_PYTHON=ON while configuring the build with cmake.

2. What you can do in the build folder:

   1. Just run python then import GTSAM and play around:

      import gtsam
      gtsam.__dir__()
      

   2. Run the unittests:

      python -m unittest discover
      

   3. Edit the unittests in python/gtsam/*.py and simply rerun the test. They were symlinked to <build_folder>/gtsam/*.py to facilitate fast development. python -m unittest gtsam/tests/test_Pose3.py - NOTE: You might need to re-run cmake .. if files are deleted or added.

3. Do make install and cd <gtsam_install_folder>/python. Here, you can:

   1. Run the unittests:

      python setup.py test
      

   2. Install gtsam to your current Python environment.

      python setup.py install
      

      • NOTE: It's a good idea to create a virtual environment otherwise it will be installed in your system Python's site-packages.

Matlab Wrapper

In the CMake, simply include the MatlabWrap.cmake file.

include(MatlabWrap)

This cmake file defines functions for generating MATLAB wrappers.

• wrap_and_install_library(interfaceHeader linkLibraries extraIncludeDirs extraMexFlags) Generates wrap code and compiles the wrapper.

Usage example:

`wrap_and_install_library("lba.h" "" "" "")`

Arguments:

• interfaceHeader: The relative or absolute path to the wrapper interface definition file.
• linkLibraries: Any additional libraries to link. Your project library (e.g. lba), libraries it depends on, and any necessary MATLAB libraries will be linked automatically. So normally, leave this empty.
• extraIncludeDirs: Any additional include paths required by dependent libraries that have not already been added by include_directories. Again, normally, leave this empty.
• extraMexFlags: Any additional flags to pass to the compiler when building the wrap code. Normally, leave this empty.