Looking for an algorithm (GIS)

Hello !

I'm working with a GIS and I have a pointer to structures (X,Y) that are

nodes coordinates that define an Arc:

parray[0] = (X1,Y1) (node 1)

parray[1] = (X2,Y2) (node 2)

parray[2] = (X3,Y3) (node 3)

.........

And I have the couple (from,to) that define a new "Arc".

"from" and "to" are in percent and define the beginning and the end of

the new Arc. Note that "from" can be greater than "to"

Of course, It is possible that a new node has to be defined.

How can I dynamically generate a new "parray" with these criteria ?

More generally, is there a web site where I can find these kinds of

algorithms ?

Help would be very appreciated.

PS: please send your reply to my email adress too.

--

Jean-Paul Dzisiak

CEME - Universit de Lige

Centre d'Etude et de Modlisation de l'Environnement

Sart-Tilman B5

B-4000 Lige

BELGIQUE

Tl +32 (0) 4 366 23 56

Fax +32 (0) 4 366 23 55