should pyslds list pypolyagamma in install_requires?

[mattjj]

Should we make pypolyagamma optional, instead of listing it in the install_requires argument to setup in setup.py? It might make the build/install process simpler, though users who want to do count modeling would need to install it separately (with pip install pypolyagamma). We could expand the installation instructions in the README to have these alternatives:

To install pyslds with pypolyagamma for fast inference in count data models, run

git clone https://github.com/mattjj/pyslds.git
pip install pypolyagamma -e pyslds

See the pypolyagamma build instructions to consider installing it with OpenMP support.

To install pyslds without pypolyagamma (which you can install separately later), just run

git clone https://github.com/mattjj/pyslds.git
pip install -e pyslds

[slinderman]

I made pypolyagamma optional in 99677ee. I followed the same design pattern that we used in pylds, namely, using *CountSLDS to cordon off the Pólya-gamma code.

The README still needs to be updated to include this detail.