Re: Plotting a super ellipse

*To*: mathgroup at smc.vnet.net*Subject*: [mg55185] Re: Plotting a super ellipse*From*: "Carl K. Woll" <carlw at u.washington.edu>*Date*: Wed, 16 Mar 2005 05:36:00 -0500 (EST)*Organization*: University of Washington*References*: <d0u71l$kno$1@smc.vnet.net> <d1145m$dp2$1@smc.vnet.net> <d13j99$qll$1@smc.vnet.net> <d15rlm$9hq$1@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

Peter, The OP was interested in plotting a super ellipse. The problem with your approach is that the output looks nothing like a super ellipse. The correct approach to eliminating the complex numbers that arise when taking a negative number to the power 2.5 is to wrap the variables themselves in Abs, and not the whole left hand side. Carl Woll "Peter Pein" <petsie at arcor.de> wrote in message news:d15rlm$9hq$1 at smc.vnet.net... > JC wrote: >> On Sun, 13 Mar 2005 10:20:38 +0000 (UTC), Peter Pein <petsie at arcor.de> >> wrote: > ... >>>Hi JC, >>> >>>use ImplicitPlot to plot implicitely ;-) and Abs[] to avoid imaginary >>>Parts (e.g. (-1)^(2.5)) >>> >>>ImplicitPlot[Abs[(x^2.5) + (y^2.5/1.25^2.5)] == 20., {x, -4, 4}, {y, -5, >>>5}] >> >> >> Peter, >> >> Thank you very much for taking the time to reply. >> >> Your suggestion, while not generating an error message, also did not >> plot. This is what it returned: >> >> ImplicitPlot[ >> Abs[x\^2.5` + 0.5724334022399462`\ y\^2.5`] == 20.`, {x, \(-4\), >> 4}, {y, \(-5\), 5}]\) >> >> > > Sorry, again and again I forget: I've put <<Graphics` into my init.m > file. Enter <<Graphics`ImplicitPlot` or just <<Graphics` _before_ > invoking ImplicitPlot[]. >