Re: link areas within images

Guido van Rossum (
Thu, 24 Jun 1993 13:25:45 +0200

> > Can we have coordinates the way everyone does then, i.e. 0,0 is in
> > the BOTTOM LEFT and 1,1 is at the TOP RIGHT.
> > PostScript works that way, maths work that way, etc.
> > ONLY for character grid personal computers is an inverted vertical
> > axis used, so as to add a line space for each new line instead of
> > having to subtract it. This was a frig, and I hope we can avoid
> > repeating it.
> That sounds fine by me. Does anyone else think otherwise?

It's not just character grid PCs, most bitmapped displays (e.g. X11,
Mac) do it it this way, too. My choice would depend on the kind of
coordinate system to be used; if it were directly related to pixels,
let Y point down, but if you normalize to e.g. [0.0, 1.0] then Y would
best point up, in correspondence with standard graph conventions.
(Just trying to settle the argument with facts instead of personal

--Guido van Rossum, CWI, Amsterdam <>