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]] >