Change internal space/origin when using sft.to_x() with an empty sft.

[EmmaRenauld]

When using an empty SFT, internal space (sft._space) is never modified. Changing this ensures that we can compare the compatibility of many SFT, even when some are empty.

Same with origin.

[arokem]

This makes sense to me! Any chance to get a test of this functionality?

[codecov]

Codecov Report

Merging #2864 (c54afdc) into master (a05e39d) will increase coverage by 0.00%.
The diff coverage is 100.00%.

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #2864   +/-   ##
=======================================
  Coverage   81.48%   81.48%           
=======================================
  Files         144      144           
  Lines       20055    20054    -1     
  Branches     3192     3192           
=======================================
  Hits        16341    16341           
  Misses       2906     2906           
+ Partials      808      807    -1     

Files Changed	Coverage Δ
dipy/io/stateful_tractogram.py	75.37% <100.00%> (+0.18%)	⬆️

[frheault]

Good catch ! This was indeed an oversight !

[EmmaRenauld]

What type of test would you like? Here is an example of previous problematic usage:

sft1 = load_tractogram(some_path)
sft2 = sft1.from_sft([], sft)

print(sft1.space) --> RASMM
print(sft2.space) --> RASMM

sft1.to_vox()
sft2.to_vox()

print(sft1.space) --> VOX
print(sft2.space) --> RASMM

print(StatefulTractogram.are_compatible(sft1, sft2))  --> FALSE

I could add these lines somewhere, they should now be compatible. Where should I add it?

Can you help me understand why the Github tests were not successful?

[skoudoro]

Can you help me understand why the Github tests were not successful?

You can ignore, this is not due to your PR. it seems there is an incompatibility between cvxpy and scipy on conda. We might need to pin specific version to avoid this issue

[skoudoro]

I could add these lines somewhere, they should now be compatible. Where should I add it?

You can add a new test in https://github.com/dipy/dipy/blob/master/dipy/io/tests/test_stateful_tractogram.py

Thanks !

[skoudoro]

Thank you for the update @EmmaRenauld.

Looks good to me. I will wait until Monday to merge it in case there are any additional comments.