Re: Polar Plot
- To: mathgroup at smc.vnet.net
- Subject: [mg82741] Re: Polar Plot
- From: Peter Pein <petsie at dordos.net>
- Date: Tue, 30 Oct 2007 03:29:17 -0500 (EST)
- References: <fg4dhs$6dc$1@smc.vnet.net>
Miguel schrieb:
> How can I to plot a polar expresion in implicit form. For example,
> r^2==3+2*r*Cos[teta]
>
>
Hello Miguel,
in Version 5.2
In[1]:=
xy = Simplify[Expand[{x, y} /.
{ToRules[Reduce[{r^2 == 3 + 2*r*Cos[t], x == r*Cos[t], y == r*Sin[t]},
{t, r, x, y}, Backsubstitution -> True]]}]]
Out[1]=
{{Cos[t]*(Cos[t] - Sqrt[3 + Cos[t]^2]), (Cos[t] - Sqrt[3 +
Cos[t]^2])*Sin[t]},
{Cos[t]*(Cos[t] + Sqrt[3 + Cos[t]^2]), (Cos[t] + Sqrt[3 +
Cos[t]^2])*Sin[t]}}
In[2]:=
ParametricPlot[Evaluate[xy], {t, 0, Pi}, AspectRatio -> Automatic]
works well.
Peter