PyMC Warning causing simulations to run very slowly


When I use pymc on Pycharm, I get the following warning:
WARNING (pytensor.tensor.blas): Using NumPy C-API based implementation for BLAS functions.

Can can i fix this as it is causing my MCMC simulations to run very slow.

When I checked my PATH, I get this on my Macbook:
% echo $PATH


Can you please help?


1 Like

Hi Patrick, I’d recommend creating a fresh conda environment (you can use one of the environment configuration files in the “conda-envs” subdirectory). The conda packages will set you up with a numpy that has BLAS configured.

Hi Patrick,

The warning you’re seeing means PyMC is using a slower method for calculations, which is making your simulations run slowly. To fix this, you can install a faster math library called BLAS. Here’s a guide to help you set it up on your Macbook: Link to guide.

This should speed up your simulations!

Best regards,