scipy.io.loadmat for Matlab 7.3

Is your feature request related to a problem? Please describe. Currently, scipy is unable to load MATLAB files that are saved with the new MATLAB file format. Attempting to load them will raise an

NotImplementedError: Please use HDF reader for matlab v7.3 files

Describe the solution you’d like

I’ve implemented a small library that can also load MATLAB 7.3 https://github.com/skjerns/mat7.3 , using h5py. It will load all data with the indicated MATLAB datatype into a dict, so similar to scipy.io.loadmat.

Do you think it makes sense to integrate this directly into scipy?

Describe alternatives you’ve considered

Just leaving it as it is might be actually okay, as adding it would introduce a dependency on h5py (which is not a dependency of scipy afaik?). what do you think?

[matthew-brett]

I don’t think we should add the h5py dependency unconditionally, but it could work as an optional dependency, so it gives an error message when h5py is not installed, suggesting the user install it.

The output should be consistent with the current output for other .mat files, unless there’s a good reason for that not to be true.

[pv]

Retaining backward compatibility is a constraint in additions, though. Adding new loading options, and changing behavior in previously undefined cases is generally easy, otherwise painful as how to do the transition needs to be planned and justified.