It sounds to me that you want to have a contour plot which takes as input the r,theta, and T.  I would suggest just 

On 6/26/07, Lorenzo Isella <> wrote:
Thanks for your suggestion, but I still have a problem.
Maybe I did not make myself clear (or most likely I have a problem
about how to implement your suggestion): actually I have T=T(r,theta)
and I would like to make a 2D plot using colors such that one can see
that the domain where I am plotting is actually a circle.
The example I mentioned is not exactly what I need since there one can
find how to plot in polar coordinates a function of r alone.
Furthermore, I do not have necessarily an equally spaced grid.
For instance, let me consider the case of 5 theta's and 7 radial
position and consequentely 35 values of T:

          theta                             R
0.000000000000000000e+00 0.000000000000000000e+00 5.459815003314423620e+01
0.000000000000000000e+00 1.666666666666666574e-01 4.853828855239110851e+01
0.000000000000000000e+00 3.333333333333333148e-01 4.315101251901344881e+01
0.000000000000000000e+00 5.000000000000000000e-01 3.836167151642037965e+01
0.000000000000000000e+00 6.666666666666666297e-01 3.410390059527122020e+01
0.000000000000000000e+00 8.333333333333332593e-01 3.031870066752165016e+01
0.000000000000000000e+00 1.000000000000000000e+00 2.695362096775039973e+01
1.570796326794896558e+00 0.000000000000000000e+00 2.396203225329512776e+01
1.570796326794896558e+00 1.666666666666666574e-01 2.130248067207563523e+01
1.570796326794896558e+00 3.333333333333333148e-01 1.893811334477913277e+01
1.570796326794896558e+00 5.000000000000000000e-01 1.683616770181326316e+01
1.570796326794896558e+00 6.666666666666666297e-01 1.496751749887080329e+01
1.570796326794896558e+00 8.333333333333332593e-01 1.330626922033307302e+01
1.570796326794896558e+00 1.000000000000000000e+00 1.182940327795447999e+01
3.141592653589793116e+00 0.000000000000000000e+00 1.051645503298913731e+01
3.141592653589793116e+00 1.666666666666666574e-01 9.349231221746512333e+00
3.141592653589793116e+00 3.333333333333333148e-01 8.311557855141172624e+00
3.141592653589793116e+00 5.000000000000000000e-01 7.389056098930650407e+00
3.141592653589793116e+00 6.666666666666666297e-01 6.568943029058285532e+00
3.141592653589793116e+00 8.333333333333332593e-01 5.839854501207304871e+00
3.141592653589793116e+00 1.000000000000000000e+00 5.191687680104649871e+00
4.712388980384689674e+00 0.000000000000000000e+00 4.615461046534314882e+00
4.712388980384689674e+00 1.666666666666666574e-01 4.103189942205120566e+00
4.712388980384689674e+00 3.333333333333333148e-01 3.647775927922803252e+00
4.712388980384689674e+00 5.000000000000000000e-01 3.242908421924544982e+00
4.712388980384689674e+00 6.666666666666666297e-01 2.882977255397825012e+00
4.712388980384689674e+00 8.333333333333332593e-01 2.562994933482758420e+00
4.712388980384689674e+00 1.000000000000000000e+00 2.278527524544009530e+00
6.283185307179586232e+00 0.000000000000000000e+00 2.025633220058637107e+00
6.283185307179586232e+00 1.666666666666666574e-01 1.800807713756398032e+00
6.283185307179586232e+00 3.333333333333333148e-01 1.600935643142084031e+00
6.283185307179586232e+00 5.000000000000000000e-01 1.423247420534685892e+00
6.283185307179586232e+00 6.666666666666666297e-01 1.265280855439646635e+00
6.283185307179586232e+00 8.333333333333332593e-01 1.124847036463023642e+00
6.283185307179586232e+00 1.000000000000000000e+00 1.000000000000000000e+00

How would you plot them in order to have a 2D-color plot where one can
understand we are working on a circle (well, maybe it will look like
something different since I have only a few grid points, but the aim
is clear, I hope)?
Kind Regards


On 26/06/07, Benoit Donnet <> wrote:
> Hey,
> That's quite simple.  Assume your file containing the data is name
> Data.dat and is in the same directory than your python script.
> from pylab import *
> from numpy import *
> tab = load('Data.dat') #load the file
> r = tab[:,0] #get the r coordinates
> theta = tab[:,1] #get the theta coordinates
> T =  tab[:,2] #get the temperature
> # now, you can process/plot your data
> Hope this help.
> Best regards.
> Benoit
> Le 25-juin-07 à 19:03, Lorenzo Isella a écrit :
> > Dear All,
> > I am quite a newbie about Python and Pylab, but I am starting to like
> > the ease you can develop with using these tools.
> > I am interested in 2D radial plots (think for instance about the plot
> > of the temperature along the cross-section of a pipe).
> > I had a look at the tutorial online, in particular to the case
> > described in:
> >
> >
> >
> > but there is something which is not 100% clear to me.
> > What if, instead of having an analytical expression for the quantity I
> > want to plot I have to read it (together with the r and theta
> > coordinates) from a file, e.g.:
> >
> > r      theta       T
> >
> >
> > where the columns r and theta contain the list of (r,theta)
> > coordinates (the "grid" I am using along the cross section) and T the
> > temperature evaluated at that grid point?
> > If necessary, I can post an example file (but at the moment I am
> > working with fairly big files and I think I conveyed an idea of what I
> > am after).
> > Many thanks
> >
> > Lorenzo
> >
> > ----------------------------------------------------------------------
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> --
> Dr. Benoit Donnet
> Université Catholique de Louvain (UCL)
> Faculté des Sciences Appliquées - Département d'Ingénierie
> Informatique (INGI)
> Place Sainte Barbe, 2
> 1348 Louvain-la-Neuve
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