Apply new validation to metrics.pairwise_kernels by csadorf · Pull Request #8050 · NVIDIA/cuml

csadorf · 2026-05-05T21:11:54Z

Apply new input validation to cuml.metrics.pairwise_kernels.

Part of #7998

Replace the legacy input_to_cupy_array calls in cuml.metrics.pairwise_kernels with check_array from cuml.internals.validation, matching the pattern established by the regression, _classification, _ranking, confusion_matrix, and hinge_loss migrations (xref NVIDIA#7998). Matches sklearn behavior: non-finite inputs (NaN, inf) now raise ValueError, consistent with sklearn.metrics.pairwise.pairwise_kernels defaults.

coderabbitai · 2026-05-05T21:14:50Z

📝 Walkthrough

Summary by CodeRabbit

Chores
- Updated copyright year.
Refactor
- Enhanced input validation handling for kernel metric functions. Full backward compatibility maintained with no API changes.

Walkthrough

The pairwise_kernels.py file updates its copyright year to 2026 and replaces the input_to_cupy_array import with check_array from cuml.internals.validation. The pairwise_kernels function refactors input validation to use check_array for both X and Y parameters, with Y set to X when not provided. No public API signatures or core kernel logic changed.

Changes

Input Validation Refactoring

Layer / File(s)	Summary
Imports `python/cuml/cuml/metrics/pairwise_kernels.py`	Import changed from `input_to_cupy_array` to `check_array` from `cuml.internals.validation`.
Core Implementation `python/cuml/cuml/metrics/pairwise_kernels.py`	`pairwise_kernels` function refactored: X is validated via `check_array`; Y is validated if provided, otherwise set to X. Previous `input_to_cupy_array` calls replaced.
Metadata `python/cuml/cuml/metrics/pairwise_kernels.py`	Copyright year updated in file header from 2022-2025 to 2022-2026.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~5 minutes

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title 'Apply new validation to metrics.pairwise_kernels' directly and specifically describes the main change in the PR, which is applying new input validation to the pairwise_kernels function.
Description check	✅ Passed	The description 'Apply new input validation to cuml.metrics.pairwise_kernels. Part of `#7998`' is directly related to the changeset, which replaces legacy input_to_cupy_array with check_array validation.
Docstring Coverage	✅ Passed	Docstring coverage is 100.00% which is sufficient. The required threshold is 80.00%.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

_{✏️ Tip: You can configure your own custom pre-merge checks in the settings.}

✨ Finishing Touches

🧪 Generate unit tests (beta)

Create PR with unit tests

_{Comment @coderabbitai help to get the list of available commands and usage tips.}

coderabbitai

Actionable comments posted: 1

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@python/cuml/cuml/metrics/pairwise_kernels.py`:
- Around line 278-283: The validation path drops the previous dtype coercion so
Y is no longer converted to X.dtype and the convert_dtype behavior is ignored;
when validating Y inside pairwise_kernels, call check_array with the dtype
matching X (e.g., check_array(Y, input_name="Y", dtype=X.dtype)) or pass the
existing convert_dtype flag into check_array so Y is coerced to X.dtype,
ensuring X and Y keep the same dtype and preserving the original mixed-dtype
behavior.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

Push a commit to this branch (recommended)
Create a new PR with the fixes

ℹ️ Review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Enterprise

Run ID: dd6e5f51-3ddc-4556-88d9-e9c28681600d

📥 Commits

Reviewing files that changed from the base of the PR and between f39dde1 and 4e86dd3.

📒 Files selected for processing (1)

python/cuml/cuml/metrics/pairwise_kernels.py

coderabbitai · 2026-05-05T21:14:56Z

+    X = check_array(X, input_name="X")
    if Y is None:
        Y = X
    else:
-        Y = input_to_cupy_array(Y).array
+        Y = check_array(Y, input_name="Y")
    if X.shape[1] != Y.shape[1]:


⚠️ Potential issue | 🟠 Major | ⚡ Quick win

convert_dtype behavior was dropped in the new validation path.

At Line 282, Y is validated but never coerced to X.dtype, so convert_dtype (Line 187) is effectively ignored. That changes prior mixed-dtype behavior and breaks the function’s documented contract.

Proposed fix

X = check_array(X, input_name="X") if Y is None: Y = X else: Y = check_array(Y, input_name="Y") + if convert_dtype and Y.dtype != X.dtype: + Y = Y.astype(X.dtype, copy=False)

As per coding guidelines, “API breaking changes to Python estimator interfaces … or breaking backward compatibility require at least one release cycle for deprecations.”

📝 Committable suggestion

‼️ IMPORTANT
Carefully review the code before committing. Ensure that it accurately replaces the highlighted code, contains no missing lines, and has no issues with indentation. Thoroughly test & benchmark the code to ensure it meets the requirements.

Suggested change

X = check_array(X, input_name="X")

if Y is None:

Y = X

else:

Y = input_to_cupy_array(Y).array

Y = check_array(Y, input_name="Y")

if X.shape[1] != Y.shape[1]:

X = check_array(X, input_name="X")

if Y is None:

Y = X

else:

Y = check_array(Y, input_name="Y")

if convert_dtype and Y.dtype != X.dtype:

Y = Y.astype(X.dtype, copy=False)

if X.shape[1] != Y.shape[1]:

🤖 Prompt for AI Agents

Verify each finding against current code. Fix only still-valid issues, skip the rest with a brief reason, keep changes minimal, and validate. In `@python/cuml/cuml/metrics/pairwise_kernels.py` around lines 278 - 283, The validation path drops the previous dtype coercion so Y is no longer converted to X.dtype and the convert_dtype behavior is ignored; when validating Y inside pairwise_kernels, call check_array with the dtype matching X (e.g., check_array(Y, input_name="Y", dtype=X.dtype)) or pass the existing convert_dtype flag into check_array so Y is coerced to X.dtype, ensuring X and Y keep the same dtype and preserving the original mixed-dtype behavior.

jcrist

jcrist · 2026-05-06T01:58:29Z

/merge

csadorf requested a review from a team as a code owner May 5, 2026 21:11

csadorf requested a review from betatim May 5, 2026 21:11

github-actions Bot assigned csadorf May 5, 2026

csadorf added improvement Improvement / enhancement to an existing function non-breaking Non-breaking change labels May 5, 2026

github-actions Bot added the Cython / Python Cython or Python issue label May 5, 2026

coderabbitai Bot reviewed May 5, 2026

View reviewed changes

jcrist approved these changes May 6, 2026

View reviewed changes

rapids-bot Bot merged commit 6daff92 into NVIDIA:main May 6, 2026
96 checks passed

This was referenced May 6, 2026

Apply new input validation to metrics.regression #8044

Merged

Apply new validation to metrics.confusion_matrix #8049

Merged

Apply new input validation to cuml.metrics.cluster #8059

Merged

Apply new validation to metrics.pairwise_distances #8061

Closed

csadorf deleted the issue-7998-apply-new-validation-to-metrics-pairwise-kernels branch May 6, 2026 21:35

This was referenced May 6, 2026

Cleanup and apply new validation to cuml._thirdparty and cuml.preprocessing #8052

Merged

A few validation fixups #8066

Merged

Navigation Menu

Uh oh!

Apply new validation to metrics.pairwise_kernels - #8050

Apply new validation to metrics.pairwise_kernels#8050
rapids-bot[bot] merged 1 commit into
NVIDIA:mainfrom
csadorf:issue-7998-apply-new-validation-to-metrics-pairwise-kernels

csadorf commented May 5, 2026

Uh oh!

coderabbitai Bot commented May 5, 2026

Summary by CodeRabbit

Walkthrough

Changes

Estimated code review effort

Uh oh!

coderabbitai Bot left a comment

Uh oh!

coderabbitai Bot May 5, 2026

Uh oh!

jcrist left a comment

Uh oh!

jcrist commented May 6, 2026

Uh oh!

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

4 participants

Uh oh!

Conversation

csadorf commented May 5, 2026

Uh oh!

coderabbitai Bot commented May 5, 2026

Summary by CodeRabbit

Walkthrough

Changes

Estimated code review effort

Uh oh!

coderabbitai Bot left a comment

Choose a reason for hiding this comment

Uh oh!

coderabbitai Bot May 5, 2026

Choose a reason for hiding this comment

Uh oh!

jcrist left a comment

Choose a reason for hiding this comment

Uh oh!

jcrist commented May 6, 2026

Uh oh!

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

4 participants