Re: What do I do to get better curves?
- To: mathgroup at smc.vnet.net
- Subject: [mg120943] Re: What do I do to get better curves?
- From: "Kevin J. McCann" <Kevin.McCann at umbc.edu>
- Date: Thu, 18 Aug 2011 03:22:41 -0400 (EDT)
- Delivered-to: l-mathgroup@mail-archive0.wolfram.com
- References: <j2g371$1ek$1@smc.vnet.net>
Here is what you want, I think: ContourPlot[Chop[a[k, w]] == 0, {w, 0, 6}, {k, 0, 3}, PlotRange -> All, PlotPoints -> 200, GridLines -> Automatic] You can include more points to get the diagonal "boundary" better defined. Kevin On 8/17/2011 5:55 AM, becko wrote: > Run the following code in mathematica: > > r=6197/3122; > p[k_,w_]:=Sqrt[w^2/r^2-k^2];q[k_,w_]:=Sqrt[w^2-k^2]; > a[k_,w_,p_,q_]:=(k^2-w^2)^2 Sin[p]Cos[q]+4k^2 p q Cos[p]Sin[q] > a[k_,w_]:=a[k,w,p[k,w],q[k,w]]; > ContourPlot[a[k,w]==0,{w,0,6},{k,0,14}] > > The curves thus obtained are very inaccurate. I tried raising the > PlotPoints and WorkingPrecision opions of ContourPlot, but it doesn't > work. Morevoer, you see that the only parameter that shows up, 'r', is > an exact rational number. I don't know what else to try. Thanks. >