Re: A bug in ListPlot3D ?

*To*: mathgroup at smc.vnet.net*Subject*: [mg65920] Re: [mg65906] A bug in ListPlot3D ?*From*: "David Park" <djmp at earthlink.net>*Date*: Sun, 23 Apr 2006 06:17:34 -0400 (EDT)*Sender*: owner-wri-mathgroup at wolfram.com

The plot looks all right to me. It is easy to misinterpret what ListPlot3D does. You have a 3 x 4 matrix of numbers. EACH and EVERY element in the array represents a z value. So the z range goes from -3 to 60. The x and y ranges go from 1 to the number of elements in each level of the array. That is, x goes from 1 to 3 and y goes from 1 to 4. Note that the three numbers you have in each list DO NOT represent the coordinates of a point. The data sample as you presented it does not contain any information as to what the x and y domains are. If you wanted to specify what they were you could use the MeshRange option in the plot. You may need to fit a surface to your data. We would have to know more about the nature of your actual data. You may have to use DeLaunayTriangulation. David Park djmp at earthlink.net http://home.earthlink.net/~djmp/ From: Hui Fang [mailto:fangh73 at xmu.edu.cn] To: mathgroup at smc.vnet.net I'm trying to use ListPlot3D to show a interesting surface. However, the result is very confusing. Since my data is rather long, I'll just use 4 points to explain what happened. ListPlot3D[{{3,55,-3},{3,60,-3},{4,55,-2},{4,60,-2.5}}] The range of x and y axes are between {1,3} and {1,4} respectively, but the y axes is supposed to be about 60! The worse thing is the z axis has a range from 1 to 60, not showing anything NEGATIVE! Anybody has any idea what's going on? I am using Mathematica 4.1. Thanks a lot! Dr. H. Fang Department of Physics Xiamen Univeristy Xiamen, Fujian 361005