array_series_matmul

Author: Ming Li
Origin: upstream
Bug-Debian: https://bugs.debian.org/923708
Forwarded: not-needed


Gbp-Pq: Name array_series_matmul.patch

Author: Debian Science Team

pandas/core/series.py

@@ -2058,7 +2058,7 @@ def __matmul__(self, other):
 
     def __rmatmul__(self, other):
         """ Matrix multiplication using binary `@` operator in Python>=3.5 """
-        return self.dot(other)
+        return self.dot(np.transpose(other)).T
 
     @Substitution(klass='Series')
     @Appender(base._shared_docs['searchsorted'])

pandas/tests/series/test_analytics.py

@@ -950,6 +950,11 @@ def test_matmul(self):
         expected = np.dot(a.values, a.values)
         assert_almost_equal(result, expected)
 
+        # np.array (matrix) @ Series (__rmatmul__)
+        result = operator.matmul(b.T.values, a)
+        expected = np.dot(b.T.values, a.values)
+        assert_almost_equal(result, expected)
+
         # mixed dtype DataFrame @ Series
         a['p'] = int(a.p)
         result = operator.matmul(b.T, a)