Re: Polar diagram contour plots?
- To: mathgroup at smc.vnet.net
- Subject: [mg34620] Re: Polar diagram contour plots?
- From: wempenj at asme.org (JDW)
- Date: Wed, 29 May 2002 02:47:09 -0400 (EDT)
- References: <acsglk$kc9$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
heimann at ism.tu-berlin.de (Justus Heimann) wrote in message news:<acsglk$kc9$1 at smc.vnet.net>...
> Hi to you All,
>
> I wonder if it is possible to plot polar diagrams as 3D and contour
> plots within Mathematica 4.0.
>
> Imagine we have a list of discrete points given along radian cuts in
> the polar plane. In my case this is a plain Ascii data table generated
> by a different code. In Mathematica form this would look like, e.g.
>
> foo = Table[Random[], {alpha, 0., 2.*Pi, dalpha}, {r, 0., rmax, dr}];
>
> These data now can easily be transformed between polar and cartesian
> form, like
>
> cartesian -> polar:
> -------------------
> r = (x^2 + y^2)^(1/2)
> alpha = Arctan[y/x]
>
> polar -> cartesian:
> -------------------
> x = r Cos[alpha]
> y = r Sin[alpha]
>
> What I desire is a 3d graph like ListPlot3D[] and 2d contour plots
> like ListContourPlot[] or ListDensityPlot[] would generate. But not on
> a cartesian grid but on a polar grid. The contour plots should show a
> legend, favourable the colour scale, in addition.
>
> Unfortunately, I can't find any Mathematica function to do the job
> like expected. Does anyone know a workaround ? Any help is very much
> desired.
>
> Many thanks
> Justus
Justus,
<< Graphics`
The function, PolarMap[Identity, {0, 1}, {0, 2 Pi}], in the Graphics Package
will generate a polar coordinate system graphic then you may use
Show[] to display multiple graphic objects.
JDW