matplotlib-users

[Matplotlib-users] Problems using triplot from file

[radfahrer <cl...@m-...>]

Hi everybody,
I am trying to plot a triangular grid from a textfile using triplot, but all
I get is some wired straight line

code:

import numpy as np
import matplotlib.pyplot as plt

x, y = np.loadtxt('points.dat', unpack=True)
triangles = np.loadtxt('triangles.dat', dtype=np.int32)

plt.triplot(x, y, triangles, 'go-')

Thanks


http://old.nabble.com/file/p29815755/points.dat points.dat 
http://old.nabble.com/file/p29815755/triangles.dat triangles.dat 


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Re: [Matplotlib-users] Problems using triplot from file

[Ian T. <ian...@gm...>]

On 27 September 2010 15:37, radfahrer <cl...@m-...> wrote:

> I am trying to plot a triangular grid from a textfile using triplot, but
> all
> I get is some wired straight line
>

Your triangulation consists of just two triangles, the first with vertices
(0, 0) (0.1, 0.1) (0.1, 0.1) and the second (0, 0), (0.1, 0.1), (0, 0).
Each of these triangles has duplicate vertices and is therefore a straight
line.

In fact you only have three distinct points in your points.dat file, at (0,
0), (0.05, 0.05), and (0.1, 0.1).  You can never construct a triangle which
isn't a straight line with these points.  Perhaps you intended your
points.dat file to be something like

0  0
0  0.05
0  0.1
0.05 0
0.05  0.05
0.05  0.1
0.1  0
0.1  0.05
0.1  0.1

Ian