Merge pull request #21232 from ganesh-k13/bug_21051_kron

BUG: Fixes `ValueError` in `np.kron`

1 files changed, 27 insertions, 0 deletions

diff --git a/numpy/lib/tests/test_shape_base.py b/numpy/lib/tests/test_shape_base.py
index a148e53da..564cdfeea 100644
--- a/numpy/lib/tests/test_shape_base.py
+++ b/numpy/lib/tests/test_shape_base.py
@@ -655,6 +655,33 @@ class TestKron:
         assert_equal(type(kron(a, ma)), np.ndarray)
         assert_equal(type(kron(ma, a)), myarray)
 
+    def test_kron_smoke(self):
+        a = np.ones([3, 3])
+        b = np.ones([3, 3])
+        k = np.ones([9, 9])
+
+        assert np.array_equal(np.kron(a, b), k), "Smoke test for kron failed"
+
+    @pytest.mark.parametrize(
+        "shape_a,shape_b", [
+            ((1, 1), (1, 1)),
+            ((1, 2, 3), (4, 5, 6)),
+            ((2, 2), (2, 2, 2)),
+            ((1, 0), (1, 1)),
+            ((2, 0, 2), (2, 2)),
+            ((2, 0, 0, 2), (2, 0, 2)),
+        ])
+    def test_kron_shape(self, shape_a, shape_b):
+        a = np.ones(shape_a)
+        b = np.ones(shape_b)
+        normalised_shape_a = (1,) * max(0, len(shape_b)-len(shape_a)) + shape_a
+        normalised_shape_b = (1,) * max(0, len(shape_a)-len(shape_b)) + shape_b
+        expected_shape = np.multiply(normalised_shape_a, normalised_shape_b)
+
+        k = np.kron(a, b)
+        assert np.array_equal(
+                k.shape, expected_shape), "Unexpected shape from kron"
+
 
 class TestTile:
     def test_basic(self):