[Python-Dev] Re: [Fwd: Discussion: Introducing new operators formatrix computation]

Thomas Wouters thomas@xs4all.net
Fri, 14 Jul 2000 16:20:17 +0200

On Fri, Jul 14, 2000 at 03:09:10AM -0700, Ka-Ping Yee wrote:

> I actually believe

>     solve(X.H()*X, X.H()*y)

> is *clearer* than

>     (X'*X)\(X'*y)

> (What does the backslash mean?  What does the tick mark mean?
> At least solve() is clear, and if i understood what H() stood
> for, it would mean more than a tick mark.)

More importantly, how are they grouped ? Is '* a single operator, or is ' a
binary operator and * an unary operator ? Or is ' a postfix unary operator
and * the binary operator ? Does the backslash escape the opening paren for
some reason, or is it an operator on its own ?

Oh, wait, I see it now ! It's a string literal of the new 'X' type,
containing '*X)\(X', multiplied by y! I wonder what that 'X' type string
is... Maybe a built-in regular expression ?

Confusing-ly y'rs,
Thomas Wouters <thomas@xs4all.net>

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