pickel@mcnc.org (Lisa C. Pickel) (05/20/89)
Can anyone recommend some algorithms/books on producing contour plots? I think I understand the "triangles method", but unfortunately my data is not on a regular, rectangular grid. Code on which I could hack would also be more than welcome. Thanks in advance, Lisa Pickel pickel@mcnc.org decvax!mcnc!pickel
haletky@mrsvr.UUCP (Ed Haletky) (05/22/89)
From article <4487@alvin.mcnc.org>, by pickel@mcnc.org (Lisa C. Pickel): > Can anyone recommend some algorithms/books on producing contour > plots? I think I understand the "triangles method", but unfortunately > my data is not on a regular, rectangular grid. > > Code on which I could hack would also be more than welcome. > > Thanks in advance, > Lisa Pickel > pickel@mcnc.org > decvax!mcnc!pickel You do not need a regular, rectangular grid to use the triangle method. The data must form a triangle. Most of the time I have used the triangle method I have been using 3d coordinates. I only concern myself with 2d of the 3d. The third dimension can be ignored. Unless it is important to you. Here is the example: I had a 3d non-rectangular, skewed mesh with a wave. That is how it looked physically. Computationally it was a cube. It is easy to map 3d points to a cube. Contour by triangles was then performed. I got some real nice contour plots. I know this is not a very good explanation. But without looking through tons of code it is all I have. I do have a half way decent 2d contour program, written by myself and a professor from Purdue University. Alternative methods would include: bezier curves B-splines B-spaline patches Any other curve drawing technique. Good-luck, Edward L. Haletky=================== =======Usenet:========================= GE Medical Systems |E ^| |^ U|~{uwvax}!uwmcsd4!mrsvr!haletky 3200 N. Grandview Blvd, W-826|L / | | \ S|~{texsun|sunbird|sunbrew| Waukesha, WI 53188 |H /__|||__\ A| crdgw1}!gemed!haletky ==================================^===^=====================================