Re; finding euclidean distance,better code?

[Hendrik van Rooyen]

On Saturday 29 March 2008 03:09:46 Steven D'Aprano wrote:
> On Fri, 28 Mar 2008 16:59:59 +0100, Robert Bossy wrote:
> > Gabriel Genellina wrote:
> >> That's what I said in another paragraph. "sum of coordinates" is using
> >> a different distance definition; it's the way you measure distance in a
> >> city with square blocks. I don't know if the distance itself has a
> >> name, but
> >
> > I think it is called Manhattan distance in reference of the walking
> > distance from one point to another in this city.
>
> You know, there are other cities than Manhattan. Some of them even have
> streets and blocks.

Sorry about having to dispel your illusions, but -

In Printed Circuit Board Layout jargon, the 'manhattan distance' is
the sum of the distances along the orthogonal axes between
two points on the board that should be connected.

The sum of all such distances is an idealised minimum for the
total track length on a double sided board, given that it were 
possible to lay all tracks with segments connected by vias,
making strictly increasing progress in the desired direction,
by laying x direction tracks on the one, and y direction tracks 
on the other side of the board without having to "backtrack" 
- i.e. having to "dodge around" obstacles, thereby adding 
"overshooting" segments of track.

(A via is a through plated hole that connects copper traces or 
tracks on opposite sides of the board) 

So I have met the beast, but I have no concept of its origin,
other than the mind numbing regularity of the layout of the
suburb of the city after which it seems to be named -
For all I know 'manhatten' could be a native american word that
means "net".

Have you noticed that when people say "Sorry.....but...." they are 
not normally sorry at all?

:-)

-  Hendrik