Renew the function subset_matches() in Class Subsetter

[algopert]

closes #50

[lukasalexanderweber]

I really like your approach of getting rid of get_indices_to_delete(), subset_matrix(), delete_index_from_matrix() .

I updated the subset_matches and tests to make it more compact. Please check if it works for your issue and then I think we are ready to merge :)

[algopert]

Hi Lukas.

It works well.
I think there was error in either of 3 functions deleted.

By the way, I have a question.

There will be still the values smaller than threshold in matrix matches_subset.

By my simulation, it doesn't seem to affect the results.
Anyway, I will open another issue for that.

Let's merge.

Thanks.

[algopert]

I think np.ix_() is good approach.

And I don't have a PYTHONic mindset, just trying to reduce computational complexity as an algo developer.

:)

[algopert]

Very compact solution!

[lukasalexanderweber]

Thanks a lot for your contribution!