From steinmetz!ge-dab!codas!mtune!rutgers!mcnc!xanth!kent Wed Jan 27 21:02:49 1988
Path: beowulf!steinmetz!ge-dab!codas!mtune!rutgers!mcnc!xanth!kent
From: kent@xanth.cs.odu.edu (Kent Paul Dolan)
Newsgroups: comp.graphics,comp.sources.wanted
Subject: Re: contouring program needed
Keywords: contour
Message-ID: <3805@xanth.cs.odu.edu>
Date: 28 Jan 88 02:02:49 GMT
References: <1185@cooper.cooper.EDU> <945@luth.luth.se>
Reply-To: kent@xanth.UUCP (Kent Paul Dolan)
Organization: Old Dominion University, Norfolk Va.
Lines: 54

In article <945@luth.luth.se> sow@cad.luth.se (Sven-Ove Westberg) writes:
>In article <1185@cooper.cooper.EDU> b.oconn@cooper.cooper.EDU (Bob O'Connor ) writes:
>|
>|Hi.
>|
>|	I'm looking for a contouring program.  I'm running a water quality
>|program that gives me concentrations of a pollutant at nodes on a
>|grid (finite element).  It gives me the location (x,y coordinates) and 
>|the concentration at that location.  I need to graphically display
>|the results.  The program will have to interpolate between the grid 
>|points and find points of equal concentration.  It will also probably
>|have to have some kind of curve fitting feature.
>|	If anyone out there has any programs or algorithms which can help
>|me I would appreciate it.
>|
>|Thanks in advance.
>
>If your data is similar to those from a finite element program. Use
>a postprocessor for a FE program. A good and cheap one is MOVIE.BYU
>from Brigham Young University. 
>
>Sven-Ove Westberg, CAD, University of Lulea, S-951 87 Lulea, Sweden.
>UUCP:    {uunet,mcvax}!enea!cad.luth.se!sow
>Internet: sow@cad.luth.se


Another approach that might prove fruitful:

	"Automated Contour Mapping Using Triangular Element Data
	Structures and An Interpolant Over Each Irregular Triangular
	Domain", Chris Gold, University of Alberta, et al., COMPUTER
	GRAPHICS (A Quarterly Repoirt of SIGGRAPH-ACM), Volume 11,
	Number 2, Summer 1977, (SIGGRAPH '77 PROCEEDINGS), page
	170-175.

Chris Gold's (fairly old) algorithm has a nice feature; it does not
require resampling the data onto a regular grid before the contours
are formed, thus preventing lots of well known and otherwise hard to
avoid artifacts.

A program could be written from the description, but it is probably
better to try to contact the author at:  C. L. Gold, Dept. of Geology,
University of Alberta, Edmonton, Alberta, Canada T6G 2E1, in case he
hasn't long ago moved on.

Hope this helps; the movie.byu idea is also a good one; no guarantee
it is still as cheap, but that package of programs used to go for the
copy cost, around $100, and it is a very, very nice graphics package
for scientific data display, at the least.

There is also a very nice 3D package available from NCAR (National
Center for Atmospheric Research) Boulder, Colorado, including
countouring, but I've lost further contact information there.

Kent, the man from xanth.