Re: [Matplotlib-users] 2D Radial Plots

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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 <lor...@gm...> wrote:
>
> Hello,
> 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=3DT(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
>                      T
> 0.000000000000000000e+00 0.000000000000000000e+00 5.459815003314423620e+0=
1
> 0.000000000000000000e+00 1.666666666666666574e-01 4.853828855239110851e+0=
1
> 0.000000000000000000e+00 3.333333333333333148e-01 4.315101251901344881e+0=
1
> 0.000000000000000000e+00 5.000000000000000000e-01 3.836167151642037965e+0=
1
> 0.000000000000000000e+00 6.666666666666666297e-01 3.410390059527122020e+0=
1
> 0.000000000000000000e+00 8.333333333333332593e-01 3.031870066752165016e+0=
1
> 0.000000000000000000e+00 1.000000000000000000e+00 2.695362096775039973e+0=
1
> 1.570796326794896558e+00 0.000000000000000000e+00 2.396203225329512776e+0=
1
> 1.570796326794896558e+00 1.666666666666666574e-01 2.130248067207563523e+0=
1
> 1.570796326794896558e+00 3.333333333333333148e-01 1.893811334477913277e+0=
1
> 1.570796326794896558e+00 5.000000000000000000e-01 1.683616770181326316e+0=
1
> 1.570796326794896558e+00 6.666666666666666297e-01 1.496751749887080329e+0=
1
> 1.570796326794896558e+00 8.333333333333332593e-01 1.330626922033307302e+0=
1
> 1.570796326794896558e+00 1.000000000000000000e+00 1.182940327795447999e+0=
1
> 3.141592653589793116e+00 0.000000000000000000e+00 1.051645503298913731e+0=
1
> 3.141592653589793116e+00 1.666666666666666574e-01 9.349231221746512333e+0=
0
> 3.141592653589793116e+00 3.333333333333333148e-01 8.311557855141172624e+0=
0
> 3.141592653589793116e+00 5.000000000000000000e-01 7.389056098930650407e+0=
0
> 3.141592653589793116e+00 6.666666666666666297e-01 6.568943029058285532e+0=
0
> 3.141592653589793116e+00 8.333333333333332593e-01 5.839854501207304871e+0=
0
> 3.141592653589793116e+00 1.000000000000000000e+00 5.191687680104649871e+0=
0
> 4.712388980384689674e+00 0.000000000000000000e+00 4.615461046534314882e+0=
0
> 4.712388980384689674e+00 1.666666666666666574e-01 4.103189942205120566e+0=
0
> 4.712388980384689674e+00 3.333333333333333148e-01 3.647775927922803252e+0=
0
> 4.712388980384689674e+00 5.000000000000000000e-01 3.242908421924544982e+0=
0
> 4.712388980384689674e+00 6.666666666666666297e-01 2.882977255397825012e+0=
0
> 4.712388980384689674e+00 8.333333333333332593e-01 2.562994933482758420e+0=
0
> 4.712388980384689674e+00 1.000000000000000000e+00 2.278527524544009530e+0=
0
> 6.283185307179586232e+00 0.000000000000000000e+00 2.025633220058637107e+0=
0
> 6.283185307179586232e+00 1.666666666666666574e-01 1.800807713756398032e+0=
0
> 6.283185307179586232e+00 3.333333333333333148e-01 1.600935643142084031e+0=
0
> 6.283185307179586232e+00 5.000000000000000000e-01 1.423247420534685892e+0=
0
> 6.283185307179586232e+00 6.666666666666666297e-01 1.265280855439646635e+0=
0
> 6.283185307179586232e+00 8.333333333333332593e-01 1.124847036463023642e+0=
0
> 6.283185307179586232e+00 1.000000000000000000e+00 1.000000000000000000e+0=
0
>
>
>
> 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
>
> Lorenzo
>
>
>
>
>
> On 26/06/07, Benoit Donnet <ben...@uc...> 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 =3D load('Data.dat') #load the file
> > r =3D tab[:,0] #get the r coordinates
> > theta =3D tab[:,1] #get the theta coordinates
> > T =3D  tab[:,2] #get the temperature
> >
> > # now, you can process/plot your data
> >
> > Hope this help.
> >
> > Best regards.
> >
> > Benoit
> >
> >
> > Le 25-juin-07 =E0 19:03, Lorenzo Isella a =E9crit :
> >
> > > 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:
> > >
> > > http://matplotlib.sourceforge.net/screenshots/polar_demo.py
> > >
> > > 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
> > Universit=E9 Catholique de Louvain (UCL)
> > Facult=E9 des Sciences Appliqu=E9es - D=E9partement d'Ing=E9nierie
> > Informatique (INGI)
> > Place Sainte Barbe, 2
> > 1348 Louvain-la-Neuve
> > Belgium
> > Phone: +32 10 47 87 18
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> >
> >
> >
> >
>
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