Re: PolarPlot
- To: mathgroup at smc.vnet.net
- Subject: [mg87613] Re: PolarPlot
- From: dh <dh at metrohm.ch>
- Date: Mon, 14 Apr 2008 05:45:36 -0400 (EDT)
- References: <ftmu5p$50d$1@smc.vnet.net>
Hi Bruce,
the radius in polar coordinates has to be real and positive. Therefore,
r=Sqrt[Cos[phi]] can not be the correct formula, we would get imaginary
values. To prevent this, we may e.g. write: r=Sqrt[Abs[Cos[phi]] what
gives the plot you are looking for.
hope this helps, Daniel
Bruce Colletti wrote:
> Re 6.0.2 under WinXP.
>
> I'm using the command below to plot the polar equation r^2 = 4a^2 Cos@theta. Is there a better way? Thankx.
>
> Bruce
>
> PolarPlot[{2 a Sqrt[Cos@t], -2 a Sqrt[Cos@t]}, {t, 0, 2 \[Pi]},
> PlotRange -> 7]
>