Add numpy to the setup.py 'install_required'

[Nagasaki45]

The project relies on numpy, ins't it? import tgt fails without having numpy installed.

[hbuschme]

Thanks for pointing this out and submitting a pull request. You are right, numpy is required in order to use the functions in tgt.agreement.

As the core functionality of tgt does not require numpy, I'm wondering whether we should really add numpy as a dependency to the library – it is huge. We have to think through how we will proceed on this matter: add numpy as a requirement or only loosely bundle the agreement module with the tgt package.

[Nagasaki45]

I see... Personally, considering the fact that library will usually be used in a data analysis environment I don't see a major problem in having numpy as a dependency. Otherwise, as you said, it might be better to "loosely bundle the agreement module". From what I can tell not importing it in __init__.py will solve the problem. We will have to update the docs accordingly, and maybe add a friendly message that numpy should be installed when importing the agreement module. Will be happy to submit a pull request if needed.

[mwlodarczak]

I agree that pulling in numpy is a heavy dependency for what is a relatively ancillary functionality. That said, these days numpy is easily installed with pip so it's not really that much of a big deal. We could also rewrite agreement.py to avoid using numpy completely but that'd be quite a lot of work with little gain. Marcin