Python binding ectrans4py

[AlexandreMary]

This branch, based on PRs #203 and #204, introduces the Python binding ectrans4py.

This is a Python interface to some ectrans functions, mainly the necessary routines to be able to:

• transform a spectral field into gridpoint
• transform a gridpoint field into spectral
• compute gridpoint derivatives of a field in spectral space

both for global and LAM fields.

It uses ctypesForFortran Python package for the Fortran<>Python interface.

Note: version number is duplicated in src/ectrans4py/__init__.py for now, until better solution.
Replaces PR #199

[AlexandreMary]

@samhatfield I guess I'd need to re-rebase this (commits 8f57c77 to b900eed) on top of #203 or even develop when you're done ?

[samhatfield]

Yes exactly! :) Then you can just force push to your repo and the PR will update itself.

[AlexandreMary]

OK I wait for 203 to be merged in develop then.

[samhatfield]

Hi @AlexandreMary - you can try rebasing this branch against develop now.

[AlexandreMary]

Rebasing done, branch force-pushed.
License for ctypesForFortran being switched to Apache-2.0 as requested, cf. UMR-CNRM/ctypesForFortran#6
@SebastienRietteMTO, should you take this opportunity to also switch to version 2 of ctypesForFortran ?

[AlexandreMary]

License of ctypesforFortran dependency has been switched to Apache-2.0

[samhatfield]

Because HAVE_ETRANS is a condition of the ECTRANS4PY feature, I think this if statement is not necessary.

[samhatfield]

If I understand right, HAVE_DOUBLE_PRECISION is effectively a condition for ECTRANS4PY. Why not make it "official" and put it as a condition here?