Fix TensorVariable __rmatmul__

Author: ricardoV94

pytensor/tensor/variable.py

@@ -652,7 +652,7 @@ def __matmul__(left, right):
         return at.math.matmul(left, right)
 
     def __rmatmul__(right, left):
-        return at.math.matmul(right, left)
+        return at.math.matmul(left, right)
 
     def sum(self, axis=None, dtype=None, keepdims=False, acc_dtype=None):
         """See :func:`pytensor.tensor.math.sum`."""

tests/tensor/test_variable.py

@@ -98,10 +98,15 @@ def test_infix_matmul_method():
     assert equal_computations([res], [exp_res])
 
     X_val = np.arange(2 * 3).reshape((2, 3))
-    res = as_tensor(X_val) @ y
+    res = X_val @ y
     exp_res = matmul(X_val, y)
     assert equal_computations([res], [exp_res])
 
+    y_val = np.arange(3)
+    res = X @ y_val
+    exp_res = matmul(X, y_val)
+    assert equal_computations([res], [exp_res])
+
 
 def test_empty_list_indexing():
     ynp = np.zeros((2, 2))[:, []]