Merge pull request scipy#15232 from stefanv/sparse-array-rmul

BUG: Add rmul for sparse arrays
kevarding · Dec 17, 2021 · d85cdca · d85cdca
2 parents d11a3d9 + 5bae3a4
commit d85cdca
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diff --git a/scipy/sparse/_arrays.py b/scipy/sparse/_arrays.py
@@ -46,6 +46,10 @@ def _lil_container(self):
     def __mul__(self, *args, **kwargs):
         return self.multiply(*args, **kwargs)
 
+    def __rmul__(self, *args, **kwargs):
+        return self.multiply(*args, **kwargs)
+
+
 
 def _matrix_doc_to_array(docstr):
     # For opimized builds with stripped docstrings

diff --git a/scipy/sparse/tests/test_array_api.py b/scipy/sparse/tests/test_array_api.py
@@ -103,6 +103,19 @@ def test_elementwise_mul(A):
     assert np.all((A * A).todense() == A.power(2).todense())
 
 
+@parametrize_sparrays
+def test_elementwise_rmul(A):
+    with pytest.raises(TypeError):
+        None * A
+
+    with pytest.raises(ValueError):
+        np.eye(3) * scipy.sparse.csr_array(np.arange(6).reshape(2, 3))
+
+    assert np.all((2 * A) == (A.todense() * 2))
+
+    assert np.all((A.todense() * A) == (A.todense() ** 2))
+
+
 @parametrize_sparrays
 def test_matmul(A):
     assert np.all((A @ A.T).todense() == A.dot(A.T).todense())