Getting started


The recommended way to install COMPAS is to use Anaconda/conda

$ conda config --add channels conda-forge
$ conda install COMPAS

To verify your setup, start Python from the command line and run the following:

>>> import compas
>>> import compas_rhino
>>> import compas_blender
>>> import compas_ghpython


COMPAS is still under very active development, with new versions being released frequently. Updating your installation to the latest version is easy.

$ conda update COMPAS


The update command doen’t always work as expected. If you know to which version to upgrade, just do

conda install COMPAS=0.7.0

Virtual environments

One of the reasons to use virtual environments is to isolate dependencies, to be able to create a fully reproducible setup, and to be able to work with different versions of Python and/or different versions and combinations of packages.

For example, if you work on a project that requires a specific version of Python or a specific version of a package that is incompatible with the ones required by another project, you can use environments to make sure both projects can run side-by-side without constantly having to update your entire development setup.

Create an environment named “compas-dev”.

$ conda create -n compas-dev

Create an environment with a specific version of Python

$ conda create -n compas-dev python=3.6

Install COMPAS (or other packages) for this environment

$ conda install -n compas-dev COMPAS=0.6.2

For further instructions about managing virtual environments with conda see the docs.

In any case, don’t forget to activate the envirnment when you want to use the installed functionality.

$ conda activate compas-dev

Known Issues

Plotter errors

Problem You get an error similar to the following when trying to run anything involving a Plotter (or even just matplotlib)

2019-04-02 16:10:39.181 python[2619:857913] -[NSApplication _setup:]: unrecognized selector sent to instance 0x7f8c389244b0
2019-04-02 16:10:39.183 python[2619:857913] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[NSApplication _setup:]: unrecognized selector sent to instance 0x7f8c389244b0'
*** First throw call stack:
    0   CoreFoundation                      0x00007fff33adbecd __exceptionPreprocess + 256
    1   libobjc.A.dylib                     0x00007fff5fba3720 objc_exception_throw + 48
    2   CoreFoundation                      0x00007fff33b59275 -[NSObject(NSObject) __retain_OA] + 0
    3   CoreFoundation                      0x00007fff33a7db40 ___forwarding___ + 1486
    4   CoreFoundation                      0x00007fff33a7d4e8 _CF_forwarding_prep_0 + 120
    5   libtk8.6.dylib                      0x000000011c566154 TkpInit + 324
    6   libtk8.6.dylib                      0x000000011c4be0ee Initialize + 2622
    7      0x0000000118bf3a3f _tkinter_create + 1183
    8   python                              0x000000010a706fe6 _PyMethodDef_RawFastCallKeywords + 230
    9   python                              0x000000010a8438b2 call_function + 306
    10  python                              0x000000010a841565 _PyEval_EvalFrameDefault + 46165


    60  python                              0x000000010a6d942d main + 125
    61  libdyld.dylib                       0x00007fff60c71ed9 start + 1
    62  ???                                 0x0000000000000002 0x0 + 2
libc++abi.dylib: terminating with uncaught exception of type NSException
Abort trap: 6

Solution Install


The default python provided in (Ana)conda is not a framework build. However, a framework build can easily be installed, both in the main environment and in conda envs: install (conda install and use pythonw rather than python.

To install when you create an environment do

$ conda create -n compas-dev -c conda-forge python=3.7 COMPAS

To install in an already existing environment

$ conda activate compas-dev
$ conda install