```Christophe Grandsire writes:
> >  >
> > There's no intrinsic reason why the two standards shouldn't agree, is
> > there?
>
> They do in fact, just with another orientation.
>
Well, of course.  ANY set of rectangular coordinates in a plane can be
converted into any other by an appropriate transformation, can't they?

>   It's just an unfortunate difference of convention.  When is
> > this convention of measuring from the top left of a page used, anyway?
>
> Everywhere precise typographic positioning is needed. Since pages are more
> often printed from top to bottom than from bottom to top, it's just logical
> that the origin has been chosen on top of the paper (and on the left since we
> write left-to-right).
>
> > I've never come across it.
> >
>
> Everywhere I've seen physical coordinates used on paper, they always begin at
> the top left hand corner. It's not much needed anymore with computers and such,
> but at the time you had to put lead types on a plank to print, and you usually
> began with the beginning, the top left hand corner, it's just logic that it
> should be used as origin of the coordinates.
>
Ah, that makes sense.  The obvious answer is to change all other uses
of Cartesian coordinates such that the positive vertical direction is
down. ;)
```