Re:NumPy Illustrated: The Visual Guide to NumPy
by enriquto on Tuesday December 29, 2020 @04:13PM
(#25575092)
> In my opinion it's math not python which got the matrix multiply operator wrong. It's not commutative so it shouldn't be written with the same operator as the regular product.
The "regular product" in math is never intended to be commutative (e.g., the product in a group or in a ring, and that includes the matrix product). If you want to indicate that an operator is commutative, in math, you use always the "+" operator. Thus, it is python that gets it wrong by using a blatantly commutative operator for non-commutative operations such as string concatenation. That python was designed by a mathematician adds sadness to this notational tragedy.
The "regular product" in math is never intended to be commutative (e.g., the product in a group or in a ring, and that includes the matrix product). If you want to indicate that an operator is commutative, in math, you use always the "+" operator. Thus, it is python that gets it wrong by using a blatantly commutative operator for non-commutative operations such as string concatenation. That python was designed by a mathematician adds sadness to this notational tragedy.