Re: Contour Lines

• To: mathgroup at smc.vnet.net
• Subject: [mg83627] Re: Contour Lines
• From: Oliver Ruebenkoenig <ruebenko at uni-freiburg.de>
• Date: Mon, 26 Nov 2007 03:46:13 -0500 (EST)
• References: <fi6b6f\$q2e\$1@smc.vnet.net>

```Perhaps imsFindContour or imsFindContourElements can help you

http://www.imtek.uni-freiburg.de/simulation/mathematica/IMSweb/imsTOC/Utlities/Graphics/UnstructuredPlotDocu.html

Oliver

On Fri, 23 Nov 2007, Wyn Evans wrote:

>
> How do you extract the coordinates of points making up a Contour Line as
> a List?
>
> This has been dealt with before in the archive (see e.g., )
> but the code there seems no longer to work. For example, the following is
> suggested
>
> f[x_, y_] := x^2 + 2y^2
> plot1 = ContourPlot[f[x, y], {x, -2, 2}, {y, -2, 2}, Contours -> {1},
>      ContourShading -> False, PlotPoints -> {30, 30}];
> f[x_, y_] := x^2 + 2y^2
> plot1 = ContourPlot[f[x, y], {x, -2, 2}, {y, -2, 2}, Contours -> {1},
>      ContourShading -> False, PlotPoints -> {30, 30}];
>
> Convert the ContourGraphics to Graphics and then extract the first part
> and you will see how Mathematica represents the contours.
>
> contour = First@Graphics@plot1
> (output omitted)
>
>
> I can see that the data I want (the actual coordinates) is there, but I
> can't figure how to extract it as a matrix or list.
>
>
>
>

Oliver Ruebenkoenig, <ruebenko AT uni-freiburg.de>

```

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