Re: "Connected region" puzzle

From: Michael Metcalf (metcalfmetcalf_at_compuserve.com)
Date: 02/23/05 

Date: Wed, 23 Feb 2005 18:28:08 +0100

"justabeginner" <nom_de_plume79@yahoo.co.uk> wrote in message
news:b7ff0972.0502230918.132940c9@posting.google.com...
> Hi all. I've been thinking about how to best implement an algorithm
> that can assess the connectivity of regions in a surface (and later
> on, a volume).
>
> Suppose you had a plate like a huge chessboard, with holes in it. The
> holes can be of varying size, shape and quantity. The holes and
> remaining plate material are made from either removing or leaving
> behind the chessboard squares. Think of it as a grid/Cartesian
> co-ordinate system.
>
> I am trying to design a program that would be able to count the number
> of *connected* holes. I have thought of a method but it is
> computationally inefficient and clumsy.
>
> It relies on methodically going through each square. If a hole is
> found, then it checks the 8 adjacent squares. If more holes are found,
> it goes to each one and checks for connectivity there.
>
> If you can think of a better, easier or more elegant method I would be
> fascinated to hear about it.

Relevant Pages

  • RE: "Connected region" puzzle
    ... >Suppose you had a plate like a huge chessboard, with holes in it. ... then it checks the 8 adjacent squares. ... >it goes to each one and checks for connectivity there. ... hole pairs ...? ...
    (comp.lang.fortran)
  • Re: "Connected region" puzzle
    ... > Suppose you had a plate like a huge chessboard, with holes in it. ... > behind the chessboard squares. ... > it goes to each one and checks for connectivity there. ... flag counter and a hole counter to zero. ...
    (comp.lang.fortran)
  • Re: "Connected region" puzzle
    ... > Suppose you had a plate like a huge chessboard, with holes in it. ... then it checks the 8 adjacent squares. ... > it goes to each one and checks for connectivity there. ... implementation of this algorithm is supposedly found in Appendix A.3 ...
    (comp.lang.fortran)
  • Re: My Vagabond Remodel
    ... pre-drill the holes in the orginal floor before placing the strip in the ... Also, as I'm sure you know, countersink the screws a bit below the ... I do know to countersink the holes, I pictured doing that when I read ... Looked great for a while but then the squares seemd to shrink just slightly. ...
    (rec.outdoors.rv-travel)
  • RE: "Connected region" puzzle
    ... Holes that are connected to each other count as 1 hole. ... determine the number of holes in a plate ... The original problem was to get connectivity - this ... Chris ...
    (comp.lang.fortran)