BUG: change the type of @ result from MatrixVariable to MatrixExpr
#1059
Conversation
Implements the __matmul__ method for MatrixExpr, enabling matrix multiplication using the @ operator and ensuring the result is returned as a MatrixExpr instance.
Adds tests to verify that matrix multiplication returns MatrixExpr instead of MatrixVariable for various input shapes.
Replaces isinstance checks with type() comparisons for MatrixExpr in matrix matmul return type tests to ensure exact type matching.
| # test 1D @ 1D → 0D | ||
| x = m.addMatrixVar(3) | ||
| assert type(x @ x) is MatrixExpr |
There was a problem hiding this comment.
Here, we can't use isinstance. Because MatrixVariable is a subclass of MatrixExpr.
There was a problem hiding this comment.
The result of x@x is a size 1 matrix. What type should it be, MatrixExpr or Expr?
Related to #1057
There was a problem hiding this comment.
Should isinstance(x @ x) not be True for both MatrixVariable and MatrixExpr? I personally don't mind using type, but is there actually a need?
A size 1 matrix should still be a MatrixExpr. I don't think we should be removing the matrix language for the user, as that's just going to cause confusion.
There was a problem hiding this comment.
MatrixVariable has the .vtype() method. But the x@x doesn't have this method.
So the result of x@x should be MatrixExpr, not MatrixVariable.
To test this, I use type to check x@x is a MatrixExpr.
Corrects the shapes of matrix variables in test_matrix_matmul_return_type to ensure proper 2D matrix multiplication and type assertion.
fix #1058