FEA Add array api support for jaccard score (scikit-learn#31204)

Author: OmarManzoor

doc/modules/array_api.rst

@@ -139,6 +139,7 @@ Metrics
 - :func:`sklearn.metrics.f1_score`
 - :func:`sklearn.metrics.fbeta_score`
 - :func:`sklearn.metrics.hamming_loss`
+- :func:`sklearn.metrics.jaccard_score`
 - :func:`sklearn.metrics.max_error`
 - :func:`sklearn.metrics.mean_absolute_error`
 - :func:`sklearn.metrics.mean_absolute_percentage_error`

doc/whats_new/upcoming_changes/array-api/31204.feature.rst

@@ -0,0 +1,2 @@
+- :func:`sklearn.metrics.jaccard_score` now supports Array API compatible inputs.
+  By :user:`Omar Salman <OmarManzoor>`

sklearn/metrics/_classification.py

@@ -1071,9 +1071,10 @@ def jaccard_score(
     numerator = MCM[:, 1, 1]
     denominator = MCM[:, 1, 1] + MCM[:, 0, 1] + MCM[:, 1, 0]
 
+    xp, _, device_ = get_namespace_and_device(y_true, y_pred)
     if average == "micro":
-        numerator = np.array([numerator.sum()])
-        denominator = np.array([denominator.sum()])
+        numerator = xp.asarray(xp.sum(numerator, keepdims=True), device=device_)
+        denominator = xp.asarray(xp.sum(denominator, keepdims=True), device=device_)
 
     jaccard = _prf_divide(
         numerator,
@@ -1088,14 +1089,14 @@ def jaccard_score(
         return jaccard
     if average == "weighted":
         weights = MCM[:, 1, 0] + MCM[:, 1, 1]
-        if not np.any(weights):
+        if not xp.any(weights):
             # numerator is 0, and warning should have already been issued
             weights = None
     elif average == "samples" and sample_weight is not None:
         weights = sample_weight
     else:
         weights = None
-    return float(np.average(jaccard, weights=weights))
+    return float(_average(jaccard, weights=weights, xp=xp))
 
 
 @validate_params(

sklearn/metrics/tests/test_common.py

@@ -2147,6 +2147,11 @@ def check_array_api_metric_pairwise(metric, array_namespace, device, dtype_name)
         check_array_api_multiclass_classification_metric,
         check_array_api_multilabel_classification_metric,
     ],
+    jaccard_score: [
+        check_array_api_binary_classification_metric,
+        check_array_api_multiclass_classification_metric,
+        check_array_api_multilabel_classification_metric,
+    ],
     multilabel_confusion_matrix: [
         check_array_api_binary_classification_metric,
         check_array_api_multiclass_classification_metric,