Add gammapy-all meta package

[cdeil]

@mwcraig – I think we already discussed this briefly in some other issue: For Gammapy I'd like to make something like this work:

conda install gammapy-all

which installs most optional dependencies and spares the user from having to type:

conda install gammapy naima scipy matplotlib ipython-notebook
conda install scikit-image scikit-learn pandas aplpy wcsaxes photutils

I think the way to implement this with conda is to add a separate meta-package: https://github.com/conda/conda/issues/793#issuecomment-135548546

Would it be OK to add this for Gammapy in the Astropy conda channel? If yes, what do I have to do to make this happen?

[zblz]

Given that the design is for gammapy to be an analysis environment rather than a package to be used by others, it might be worth reversing the logic, as mentioned with the package blaze in the last comment of the issue you linked: i.e., a gammapy-core package with the current dependencies, and a gammapy package that installs the whole environment (with all optional dependencies as hard dependencies).

[cdeil]

@mwcraig - This is something we're still interested in.

We want a gammapy-core package that is easy to install, and only depends on the required dependencies. And then we want a gammapy package that depends on all the ~ 10 extra optional dependencies.

Then most users will type conda install gammapy and can start doing analysis, but if there's installation issues with one of the optional dependencies (like there was with healpy and others in the past), then it's still possible to conda install gammapy-core and get a mostly working system.

@mwcraig - Is there precedent for a package doing it this way at https://github.com/OpenAstronomy/conda-channel/ ? How hard would it be to set this two-package setup up for Gammapy there?

[cdeil]

@mwcraig - I just now released Gammapy 0.4: https://pypi.python.org/pypi/gammapy/0.4

Should the conda package be updated here or in some other repo?

[mwcraig]

@cdeil -- sorry for the huge delay.

For gammapy please do a PR on astropy/conda-channel/astropy

For the meta-package open a PR here. You would need to include these sections in the meta.yaml, I think:

• package (including name and version)
• requirements (run only, should list all of the packages you want installed)

I can provide some more active help next week once classes here are done.

[mwcraig]

@cdeil -- oops, I meant you should open the meta-package PR at https://github.com/openastronomy/conda-channel