Fix Optimization Summary failing after loading from hdf5

[PaulJonasJost]

if free_indices were interpreted as floats, we could not use them to subset the array. Happened to me after loading results from hdf5

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 66.66667% with 1 lines in your changes are missing coverage. Please review.

Project coverage is 84.55%. Comparing base (cacd525) to head (d578fa5). Report is 7 commits behind head on develop.

Files	Patch %	Lines
pypesto/result/optimize.py	66.66%	1 Missing :warning:

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Additional details and impacted files

```diff @@ Coverage Diff @@ ## develop #1367 +/- ## ======================================== Coverage 84.54% 84.55% ======================================== Files 157 157 Lines 12949 12950 +1 ======================================== + Hits 10948 10950 +2 + Misses 2001 2000 -1 ```

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[dweindl]

if free_indices were interpreted as floats, we could not use them to subset the array. Happened to me after loading results from hdf5

Thanks. However, I'd prefer fixing the root of the issue, rather than the symptom. I.e., ensuring free_indices is always int.

[PaulJonasJost]

if free_indices were interpreted as floats, we could not use them to subset the array. Happened to me after loading results from hdf5

Thanks. However, I'd prefer fixing the root of the issue, rather than the symptom. I.e., ensuring free_indices is always int.

So the save function should have taken care of this. Also Problem defines their free indices as int, therefore I am not sure where it went wrong except for the integration of free indices to the Optimizer result guaranteed it here, but will have one more look whether anything else might be missing. Will still leave it in the summary as well as a second safety measure.

[dweindl]

not sure where it went wrong

I don't see either how this could become float, except for the case of empty x_free_indices, which would be fixed by adding dtype=int to https://github.com/ICB-DCM/pyPESTO/blob/872e2530e55c944ee55f0e38bdbdb479d0c7fba5/pypesto/result/optimize.py#L198.

[PaulJonasJost]

@dweindl could you re-review please :) added the dtype argument but still kept the change before as an additional safety measure.

[PaulJonasJost]

still kept the change before as an additional safety measure

I don't think it makes sense to have it there. Either we specify and ensure that problem.x_free_indices contains int and assume that everywhere, or we specify it to be of any type of number and treat it accordingly everywhere.

IMO, it does make sense to do this here, as we only now start to ensure it is int, but for backwards compatibility or previous results, it might be good to have this as an additional safety net?

[PaulJonasJost]

Closing this for now.