FIX missing order in old path

scikit-learn · May 10, 2024 · 43cadcb · 43cadcb
1 parent 4ca6e8b
commit 43cadcb
Show file tree

Hide file tree

Showing 2 changed files with 7 additions and 0 deletions.
diff --git a/sklearn/isotonic.py b/sklearn/isotonic.py
@@ -166,6 +166,7 @@ def isotonic_regression(
         sample_weight = _check_sample_weight(sample_weight, y, dtype=y.dtype, copy=True)
         sample_weight = np.ascontiguousarray(sample_weight[order])
         _inplace_contiguous_isotonic_regression(y, sample_weight)
+        y = y[order]
 
     if y_min is not None or y_max is not None:
         # Older versions of np.clip don't accept None as a bound, so use np.inf

diff --git a/sklearn/tests/test_isotonic.py b/sklearn/tests/test_isotonic.py
@@ -227,7 +227,13 @@ def test_isotonic_regression_with_ties_in_differently_sized_groups():
 
 def test_isotonic_regression_reversed():
     y = np.array([10, 9, 10, 7, 6, 6.1, 5])
+    y_result = np.array([10, 9.5, 9.5, 7, 6.05, 6.05, 5])
+
+    y_iso = isotonic_regression(y, increasing=False)
+    assert_allclose(y_iso, y_result)
+
     y_ = IsotonicRegression(increasing=False).fit_transform(np.arange(len(y)), y)
+    assert_allclose(y_, y_result)
     assert_array_equal(np.ones(y_[:-1].shape), ((y_[:-1] - y_[1:]) >= 0))