L-shaped ListContourPlot

• To: mathgroup at smc.vnet.net
• Subject: [mg97136] L-shaped ListContourPlot
• From: Flavio <flavio.cimolin at gmail.com>
• Date: Fri, 6 Mar 2009 04:24:42 -0500 (EST)

```Hello,

I have some pressure data coming from an external FE solver, which I
want to plot in Mathematica, for a L-shaped domain. I have tried to
use ListContourPlot (or ListDensityPlot), but I have found an
unexpected behaviour in controlling the shape of the domain with the
RegionFunction option. I am using Mathematica 6.0.

The command I use for the plot is the following:

ListContourPlot[data, ColorFunction -> "Rainbow", PlotRange -> All,
RegionFunction -> Function[{x, y, z}, (y < 5) || (x < 2)]]

Now... if I keep the (x < 2), everything goes well, but if I put (x <
3), instead of having an L-shaped domain, I obtain a strange oblique
boundary. Is there an explanation to this?

In order to test it, you can consider the following data:

data = {{0.`, 0.`, 39.99`}, {0.`, 1.`, 39.99`}, {0.`, 2.`,
40.4`}, {0.`, 3.`, 42.24`}, {0.`, 4.`, 41.88`}, {2.`, 0.`,
39.37`}, {2.`, 1.`, 39.32`}, {2.`, 2.`, 39.56`}, {2.`, 3.`,
44.06`}, {2.`, 4.`, 41.01`}, {4.`, 0.`, 35.72`}, {4.`, 1.`,
35.63`}, {4.`, 2.`, 35.48`}, {4.`, 3.`, 37.45`}, {4.`, 4.`,
29.15`}, {6.`, 0.`, 30.95`}, {6.`, 1.`, 30.89`}, {6.`, 2.`,
30.59`}, {6.`, 3.`, 29.59`}, {6.`, 4.`, 29.7`}, {8.`, 0.`,
27.12`}, {8.`, 1.`, 27.12`}, {8.`, 2.`, 27.03`}, {8.`, 3.`,
26.33`}, {8.`, 4.`, 26.99`}, {10.`, 0.`, 23.94`}, {10.`, 1.`,
23.93`}, {10.`, 2.`, 23.9`}, {10.`, 3.`, 23.56`}, {10.`, 4.`,
23.7`}, {12.`, 0.`, 21.05`}, {12.`, 1.`, 21.04`}, {12.`, 2.`,
20.99`}, {12.`, 3.`, 20.75`}, {12.`, 4.`, 20.64`}, {14.`, 0.`,
18.44`}, {14.`, 1.`, 18.42`}, {14.`, 2.`, 18.29`}, {14.`, 3.`,
17.82`}, {14.`, 4.`, 17.37`}, {16.`, 0.`, 16.39`}, {16.`, 1.`,
16.36`}, {16.`, 2.`, 16.07`}, {16.`, 3.`, 14.82`}, {16.`, 4.`,
12.77`}, {18.`, 0.`, 15.3`}, {18.`, 1.`, 15.28`}, {18.`, 2.`,
14.93`}, {18.`, 3.`, 12.67`}, {18.`, 4.`, 11.7`}, {20.`, 0.`,
15.15`}, {20.`, 1.`, 15.14`}, {20.`, 2.`, 14.7`}, {20.`, 3.`,
12.46`}, {20.`, 4.`, 12.08`}, {0.`, 5.`, 41.35`}, {0.`, 6.`,
40.95`}, {0.`, 7.`, 40.94`}, {0.`, 8.`, 41.23`}, {0.`, 9.`,
41.7`}, {2.`, 5.`, 37.5`}, {2.`, 6.`, 38.08`}, {2.`, 7.`,
39.48`}, {2.`, 8.`, 40.55`}, {2.`, 9.`, 41.42`}, {17.`,
5.`, -8.22`}, {17.`, 6.`, -4.96`}, {17.`, 7.`, -3.1`}, {17.`,
8.`, -1.44`}, {17.`, 9.`, -0.29`}, {19.`, 5.`, 10.19`}, {19.`,
6.`, 5.42`}, {19.`, 7.`, 2.01`}, {19.`, 8.`, 0.52`}, {19.`, 9.`,
0.09`}};