Add mogpr timestep option

[mlubej]

Changes:

• added the option for a custom timestep (provided as '5D' or '1M' etc.
• fixed a bug where the provided limited set of variables was not used to limit the data

Closes #96

(cc. @GriffinBabe I tried this out myself and it works, but it wouldn't hurt if you also give it a try)

[GriffinBabe]

In the mogpr function, there is an issue when leaving "prediction_period" as default (None): the "output_time_dimension" is not getting defined in that case. Other than that, the function seems to work fine, I ran mogpr with different prediction periods.

[mlubej]

In the mogpr function, there is an issue when leaving "prediction_period" as default (None): the "output_time_dimension" is not getting defined in that case. Other than that, the function seems to work fine, I ran mogpr with different prediction periods.

@GriffinBabe Is this based on the code review or did you encounter this during execution? It works for me in both cases.

If you ran into the issue, could you please provide a minimal example where I could test this?

[mlubej]

If you ran into the issue, could you please provide a minimal example where I could test this?

I see now I had unpushed commits...

[GriffinBabe]

Yes it works now, for me you can merge :)