BUG: IntervalIndex.unique() only contains the first interval if all interval borders are negative

[khemkaran10]

Fixes: #61917
Before FIx ❌:

idx_neg = pd.IntervalIndex.from_tuples([(-4, -3), (-4, -3), (-3, -2), (-3, -2), (-2, -1), (-2, -1)])
print(idx_neg.unique())

# Output:
# IntervalIndex([(-4, -3]], dtype='interval[int64, right]')

After Fix ✅:

idx_neg = pd.IntervalIndex.from_tuples([(-4, -3), (-4, -3), (-3, -2), (-3, -2), (-2, -1), (-2, -1)])
print(idx_neg.unique())

# output:
# IntervalIndex([(-4, -3], (-3, -2], (-2, -1]], dtype='interval[int64, right]')

• Fixes incorrect deduplication of negative-valued intervals when using .unique().

• Previously used .view("complex128"), which failed for negative floats/ints.

• closes BUG: IntervalIndex.unique() only contains the first interval if all interval borders are negative #61917

• Tests added and passed if fixing a bug or adding a new feature

• All code checks passed.

[il1sf4]

Hello @khemkaran10, I have tried your fix and I have the following issue. When i run with this branch this code:
import pandas as pd idx_neg = pd.IntervalIndex.from_tuples([(-4, -3), (-4, -3), (-3, -2), (-3, -2), (-2, -1), (-2, -1)]) print(idx_neg.unique())
I get from the last line: E ValueError: left side of interval must be <= right side
I have tried to debug the problem and I found that:
unique() from interval.py calls at the return self._from_combined(nc). the _from_combined() method from interval.py sets nc to nc = combined.view("i8").reshape(-1, 2). Here is the problem, because:
array([[-4.-3.j],
[-3.-2.j],
[-2.-1.j]])
gets transformed to:
array([[-4607182418800017408, -4609434218613702656],
[-4609434218613702656, -4611686018427387904],
[-4611686018427387904, -4616189618054758400]])
and then the method delivers an invalid Intervalindex, where left side is greater then the right side.

Gould you try to run the code again and assure, that idx_neg.unique() really returns "IntervalIndex([(-4, -3], (-3, -2], (-2, -1]], dtype='interval[int64, right]')"? In my tests the return is "IntervalIndex([([-4607182418800017408, -4609434218613702656], (-4609434218613702656, -4611686018427387904], (-4611686018427387904, -4616189618054758400]], dtype='interval[int64, right]')" which triggers the error: "E ValueError: left side of interval must be <= right side"

[khemkaran10]

@il1sf4 Thanks for pointing out. I have update the PR.

[jbrockmendel]

is the hstack really necessary here since the next 2 lines is just splitting them back up?

[khemkaran10]

thanks @jbrockmendel , It's not required. I'll change this.

[github-actions]

This pull request is stale because it has been open for thirty days with no activity. Please update and respond to this comment if you're still interested in working on this.

[il1sf4]

Issue is fixed, approved.

[il1sf4]

Dear reviewers @jbrockmendel , @mroeschke , please, check again the bugfix commits and if you have no other findings, please, approve the PR. I need this patch to be released ASAP for my project.

[il1sf4]

Why is taking so long this bugfix PR to be merged?

[johannes-mueller]

@mroeschke is there anything blocking this? This fix is needed here. Anything that we can do to get this merged?

[johannes-mueller]

@khemkaran10 are the last two comments by @jbrockmendel resolved?

[khemkaran10]

@johannes-mueller yes both are resolved.

[rhshadrach]

Gentle ping @jbrockmendel

[khemkaran10]

@rhshadrach @jbrockmendel I have made the requested changes. I think it's good to merge now.

[rhshadrach]

Is this hit by the tests?

[khemkaran10]

@rhshadrach I added this check to handle mypy failure. should I add a separate test for this one?

[johannes-mueller]

Is this check actually needed? I thought np.asarray() is doing such a check internally.