Re: extracting contour points
- To: mathgroup at smc.vnet.net
- Subject: [mg92479] Re: extracting contour points
- From: Jens-Peer Kuska <kuska at informatik.uni-leipzig.de>
- Date: Wed, 1 Oct 2008 18:31:49 -0400 (EDT)
- Organization: Uni Leipzig
- References: <gbulri$ld4$1@smc.vnet.net>
- Reply-to: kuska at informatik.uni-leipzig.de
Hi,
what Mathematica version ?
grcontour = Graphics[contour];
is useless in Version 6 and
First[grcontour] // Normal
is useless in version 5.x ??
And in your ContourPlot[] is only *one* line.
Regards
Jens
peterp wrote:
> Hello all,
>
> I've searched the group but I still have a problem. The contour sought
> below returns two lines (you can actually see them on the graphic output).
> The commands after the contour plot only extract the coordinates of one
> of the two lines. How do I get the second ?
> I tried replacing "First" by "Second" but no dice.
>
> Thanks,
> Peter
>
> f[p_, a_, x_] = - p x + x^(a + 1)
>
> contour =
> ContourPlot[Arg[f[1, .6, x + I y]], {x, -2, 2}, {y, -2, 2}, Contours
> -> {0},
> ContourShading -> False, PlotPoints -> 100]
>
> grcontour = Graphics[contour];
> InputForm[grcontour];
> lns = First[
> Cases[First[grcontour] // Normal, Line[pts_] -> pts, \
> [Infinity]]];
> dat = Table[lns];
> Export["junk.dat", Re[dat]]
>