Use MatrixGenExpr for ufunc results

Return MatrixGenExpr (not MatrixExpr) from _wrap_ufunc for ndarray ufunc results in expr.pxi, and update tests to import and expect MatrixGenExpr. This aligns unary ufunc behavior (e.g., sqrt on lists/arrays) with the generator matrix expression type and fixes related type assertions in tests.

Author: Zeroto521

src/pyscipopt/expr.pxi

@@ -871,7 +871,7 @@ cdef object _vec_to_const = np.frompyfunc(_to_const, 1, 1)
 cdef inline object _wrap_ufunc(object x, object ufunc):
     if isinstance(x, (np.ndarray, list, tuple)):
         res = ufunc(_vec_to_const(x))
-        return res.view(MatrixExpr) if isinstance(res, np.ndarray) else res
+        return res.view(MatrixGenExpr) if isinstance(res, np.ndarray) else res
     return ufunc(_to_const(x))
 
 

tests/test_expr.py

@@ -3,8 +3,8 @@
 import numpy as np
 import pytest
 
-from pyscipopt import MatrixExpr, Model, cos, exp, log, sin, sqrt
-from pyscipopt.scip import CONST, Expr, ExprCons, GenExpr
+from pyscipopt import Model, cos, exp, log, sin, sqrt
+from pyscipopt.scip import CONST, Expr, ExprCons, GenExpr, MatrixGenExpr
 
 
 @pytest.fixture(scope="module")
@@ -263,10 +263,10 @@ def test_unary(model):
     assert str(cos([[1]])) == "[[cos(1.0)]]"
 
     assert isinstance(sqrt(2), GenExpr)
-    assert isinstance(sqrt([2, 2]), MatrixExpr)
-    assert isinstance(sqrt([[2], [2]]), MatrixExpr)
-    assert isinstance(sqrt([2, x]), MatrixExpr)
-    assert isinstance(sqrt([[2], [x]]), MatrixExpr)
+    assert isinstance(sqrt([2, 2]), MatrixGenExpr)
+    assert isinstance(sqrt([[2], [2]]), MatrixGenExpr)
+    assert isinstance(sqrt([2, x]), MatrixGenExpr)
+    assert isinstance(sqrt([[2], [x]]), MatrixGenExpr)
 
     # test invalid unary operations
     with pytest.raises(TypeError):