centroids

[Michel Wurtz - ENGEES/CEREG]

Rich Shepard wrote:
> 
> On Wed, 12 Jul 2000, Michel Wurtz - ENGEES/CEREG wrote:
> 
> > What do you call centroids ?  We have currently some discussions
> > in the developpers group about the mathematical definition of the
> > centroid.  Do you mean a point inside a polygon, or the point that
> > visualy looks the more at its center ?
> 
> Michel,
> 
>   The third definition: the geometric center of the polygon. That is, where
> would you put the nail to hang the polygon by its center of mass. Sometimes,
> the center of mass is outside the polygon (as in a quarter-moon shape).

That's true, but I volontary didn't mention it because the center of
mass is totaly useless, topologicaly speaking ;-), even if it is
probably the easier to compute.

-- 
Michel Wurtz    ENGEES - CEREG
                1, quai Koch - BP 1039, F-67070 STRASBOURG cedex
                Tel: +33 03.88.24.82.45  Fax: +33 03.88.37.04.97