From: spellucci@mathematik.tu-darmstadt.de (Peter Spellucci)
Newsgroups: sci.math.num-analysis,comp.graphics.algorithms,comp.soft-sys.matlab,comp.lang.fortran
Subject: Re: Simple Mesh algorithm (still stuck !!!)
Date: 10 Dec 1998 15:40:10 GMT

In article <74ogcj$2he$1@news.tudelft.nl>,
 derijken@USA.net (Dany) writes:
|> on Sat, 05 Dec 1998 22:59:52 -0400, Joel Guerrero wrote...
|> >
|> >But why don't you try triangular meshes?.  They better and i thing esiest to
|> >generate.
|> >Try using the delaunay triangulation method.
snip 
|> I just want to mesh the surface of a rectangular object.
|> where can I find an example of this ? PLS help as much 
|> as you can .... 
|> 
|> Thanks in advance,
|> Dany
|> 
snip
the following sources will be useful

http://www-users.informatik.rwth-aachen.de/~roberts/meshgeneration.html
http://www.geom.umn.edu/
http://www.ce.cmu.edu/~sowen/
http://www.ics.uci.edu/~eppstein/geom.html
http://www.engr.usask.ca/%7Emacphed/finite/fe_resources/fe_resources.html

further i found the following in my notices

I would like to announce the release of QMG1.1.  QMG is free software
available on the Web for fully automatic unstructured finite element
mesh generation in two and three dimensions.  It can generate meshes
for complex polyhedral domains with nonmanifold features.  It includes
geometric modeling routines for polyhedral domains, two mesh
generators and a finite element solver.  QMG is written in primarily
in C++ and is a collection of m-files and mex-files that run under
Matlab 4.2.

The new features of QMG1.1 (compared to QMG1.0) are:

  (1) In addition to running under Matlab, QMG1.1 can also run under
Tcl/Tk.  Tcl is a scripting language, and Tk is a GUI-building toolkit.
Both were developed at UC-Berkeley/Sun Microsystems and are available
on the Web.
  (2) QMG1.1 runs under Microsoft Windows NT as well as Unix.  Windows
NT (i386) users can download the QMG executables directly from the Web.
  (3) QMG1.1 uses VRML and a web browser for 3D graphics.
  (4) QMG1.1 includes a Delaunay-based boundary mesh generator as well
as an octree-based volumetric mesh generator.
  (5) The 3D volumetric mesh generator in QMG1.1 runs much faster
and produces higher quality meshes than QMG1.0.
  (6) QMG1.1 supports additional simplified file formats for I/O of
geometric objects.

For more information, please see:
   http://www.cs.cornell.edu/home/vavasis/qmg-home.html

-- Steve Vavasis (vavasis@mcs.anl.gov)

----------------------------------
I guess that nethertheless you first should improve your programming skills.
your fortran code contained three errors. 
you must define "patch" as a threedimensional array  
patch(i,j,k) 1<=i<=n , 1<=j<=m, 1<=k<=3kmax  and then 
patch(i,j,1)=x_i
patch(i,j,2)=y_j
patch(i,j,3)=1  (since your z is always 1, presently)
this gives you a grid of points (i,j) in the plane with associated coordinates
x,y,z.
hope this helps
peter