Frequency Asked Questions

NumExpr has a max 32 arguments

This is a limitation due to a #define in NumPy. It can be removed by downloading the NumPy git repo, and changing NPY_MAXARGS, currently (as of NumPy 1.13) found in the file numpy/numpy/core/include/numpy/ndarraytypes.h:

https://github.com/numpy/numpy/blob/dc27edb92ec70b5c0ade8ecd1ed78884a0a0a5dc/numpy/core/include/numpy/ndarraytypes.h

Then build and install NumPy with the setup script as follows:

git clone https://github.com/numpy/numpy.git cd numpy nano numpy/core/include/numpy/ndarraytypes.h

<do your changes>

python setup.py build install

The current limit in NumExpr for the maximum number of arguments is 254.