Small bug correction

[HARSHDIPSAHA]

Description

What is this PR

• Bug fix
• Addition of a new feature
• Other

Why is this PR needed?

The _cdist function in movement/kinematics/distances.py had a semantic bug where it incorrectly assigned coordinates for the second element (elem2) in pairwise distance calculations. The function was using coordinates from array a for both elem1 and elem2, when elem2 should correctly use coordinates from array b.

While this bug may not cause functional issues in typical use cases (where both arrays come from the same dataset and have identical coordinates after xarray alignment), it represents a code correctness issue that should be fixed for:

• Semantic correctness
• Code maintainability
• Future-proofing against edge cases
• Clarity of intent

What does this PR do?

This PR fixes the coordinate assignment bug in _cdist by changing line 102 from:

elem2: getattr(a, labels_dim).values,  # Incorrect

to:

elem2: getattr(b, labels_dim).values,  # Correct

This ensures that the elem2 dimension is correctly assigned coordinates from array b's labels_dim, matching the semantic intent of the function where elem1 comes from a and elem2 comes from b.

References

• Fixes issue [BUG] Incorrect usage in cdist fuction #775
• Related to the bug analysis that identified incorrect coordinate assignment in _cdist function

How has this PR been tested?

1. Existing tests pass: All existing unit tests for _cdist continue to pass, confirming that the fix doesn't break existing functionality:

   pytest tests/test_unit/test_kinematics/test_distances.py::test_cdist_with_known_values -v

   Both test cases (individuals and keypoints dimensions) pass successfully.

Is this a breaking change?

No

Does this PR require an update to the documentation?

No...

Checklist:

• The code has been tested locally
• Tests have been added to cover all new functionality (existing tests cover this functionality)
• The documentation has been updated to reflect any changes (no documentation changes needed)
• The code has been formatted with pre-commit (no formatting issues, linting passes)

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud