Merge pull request qutip#2349 from Ericgig/misc.matmul_shapecheck

Fix logic error in shape check
gsuarezr · Mar 12, 2024 · 9f04c73 · 9f04c73
2 parents c5ec829 + 71a9bb3
commit 9f04c73
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Showing 2 changed files with 13 additions and 2 deletions.
diff --git a/qutip/core/data/matmul.pyx b/qutip/core/data/matmul.pyx
@@ -69,8 +69,10 @@ cdef int _check_shape(Data left, Data right, Data out=None) except -1 nogil:
         )
     if (
         out is not None
-        and out.shape[0] != left.shape[0]
-        and out.shape[1] != right.shape[1]
+        and (
+            out.shape[0] != left.shape[0]
+            or out.shape[1] != right.shape[1]
+        )
     ):
         raise ValueError(
             "incompatible output shape, got "

diff --git a/qutip/tests/core/data/test_dense.py b/qutip/tests/core/data/test_dense.py
@@ -305,3 +305,12 @@ def test_like_keep_order(func, fortran):
     old = dense.zeros(3, 3, fortran=fortran)
     new = func(old)
     assert new.fortran == old.fortran
+
+
+@pytest.mark.parametrize("shape", [(4, 3), (3, 3), (2, 8)])
+def test_inplace_matmul_error(shape):
+    op = dense.zeros(4, 4)
+    out = dense.zeros(*shape)
+    with pytest.raises(ValueError) as err:
+        data.matmul_dense(op, op, 1., out=out)
+    assert str(err.value).startswith("incompatible output shape")