fix(metrics): handle single-segment partitions in hausdorff and meantime#374
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gaoflow wants to merge 2 commits into
Open
fix(metrics): handle single-segment partitions in hausdorff and meantime#374gaoflow wants to merge 2 commits into
gaoflow wants to merge 2 commits into
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hausdorff() and meantime() both call cdist() on intermediate-breakpoint
arrays and then reduce over the result with .min() / .max(). When a
partition contains no intermediate breakpoints (i.e. the signal is
predicted to be a single segment), that array is empty. numpy refuses
to take the min/max of a zero-element array and raises:
ValueError: zero-size array to reduction operation minimum
which has no identity
The fix short-circuits before cdist when either array is empty:
- If both are empty (both single-segment) → distance is 0.
- If only one is empty → distance is np.inf (incomparable sets).
Tests added for hausdorff and meantime with single-segment partitions.
for more information, see https://pre-commit.ci
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Bug
hausdorff()andmeantime()crash withValueErrorwhen eitherpartition contains no intermediate breakpoints (i.e. a single-segment
prediction or ground truth):
Both functions call
scipy.spatial.distance.cdist()on the arrays ofintermediate breakpoints and then take
.min()/.max()of the result.When one array is empty (no intermediate breakpoints),
cdistreturns azero-row or zero-column matrix and
numpycannot take the min/max of anempty axis.
The
sanity_check()passes for these inputs (both lists end with the sameindex), so callers have no way to anticipate the crash.
Fix
Short-circuit before
cdistwhen either intermediate-breakpoint array isempty:
0.0np.inf(incomparable sets, by convention)Tests
Two new parametrized tests verify the edge cases for
hausdorffandmeantimedirectly. All 20 tests pass.