Re: Bug associated with Graphics3D???
- To: mathgroup at smc.vnet.net
- Subject: [mg105237] Re: [mg105210] Bug associated with Graphics3D???
- From: Syd Geraghty <sydgeraghty at me.com>
- Date: Wed, 25 Nov 2009 02:32:57 -0500 (EST)
- References: <200911241050.FAA00829@smc.vnet.net>
Wow Lou,
That was a very interesting artifact of Show[].
The key is to be found in the Possible Issues documentation for Show[].
Show uses the options from the first graphic:
So you first have to reverse the order of the shown functions!!!!
Show[Pla[x], Bloid], x] ...... that fixes the 5.1 issue !!
Do[Print[Show[Pla[x], Bloid], x], {x, 5.05, 5.15, 0.025}]; works fine!
Cheers .... Syd
Syd Geraghty B.Sc, M.Sc.
sydgeraghty at mac.com
Mathematica 7.0.1.0 for Mac OS X x86 (64 - bit) (12th September 2009)
MacOS X V 10.6.1 Snow Leopard
MacBook Pro 2.33 GHz Intel Core 2 Duo 2GB RAM
On Nov 24, 2009, at 5:50 AM, Louis Talman wrote:
> Can anyone explain why the disk that corresponds to x = 5.1 (see the
> last line of the code below) isn't red---like the others?
>
> -------------------------
>
> Rho[Psi_] = 2/(1 - Cos[Psi]);
>
> Para = ParametricPlot3D[
> Rho[Psi] {Cos[Psi], Sin[Psi] Cos[Theta], Sin[Psi] Sin[Theta]},
> {Psi, Pi/3, Pi}, {Theta, 0, 2 Pi},
> PlotStyle -> {Specularity[0.9], Opacity[0.3]}, Mesh -> None,
> Axes -> None, PlotRange -> {{-1.3, 6.7}, {-3.5, 3.5}, {-3.5,
> 3.5}}];
>
> Focus = Graphics3D[{PointSize[0.015], Point[{0, 0, 0}]}];
>
> Bloid = Show[Para, Focus];
>
> Pla[x_] := ParametricPlot3D[
> x Sec[Psi] { Cos[Psi], Sin[Psi] Cos[Theta], Sin[Psi] Sin[Theta]},
> {Theta, 0, 2 Pi}, {Psi, 0, ArcTan[(2 Sqrt[3])/x]}, Mesh -> None,
> Axes -> None, PlotStyle -> {Red, Opacity[0.6]}];
>
> Do[Print[Show[Bloid, Pla[x]]], {x, 4.8, 5.4, 0.1}];
>
> ---------------------------
>
> It also happens when x = 3.5, but for no other values of x generated
> by {x, 3.0, 6.5, 0.1}.
>
>
> --Lou Talman
> Department of Mathematical and Computer Sciences
> Metropolitan State College of Denver
>
> <http://clem.mscd.edu/%7Etalmanl>
>
>
>
- References:
- Bug associated with Graphics3D???
- From: Louis Talman <talmanl@gmail.com>
- Bug associated with Graphics3D???