Re: Combining VectorPlot3D and ParametricPlot3D

• To: mathgroup at smc.vnet.net
• Subject: [mg114009] Re: Combining VectorPlot3D and ParametricPlot3D
• From: Joseph Gwinn <joegwinn at comcast.net>
• Date: Sat, 20 Nov 2010 18:24:08 -0500 (EST)
• References: <ic8afl\$83h\$1@smc.vnet.net>

```In article <ic8afl\$83h\$1 at smc.vnet.net>, rscott <rscott at socal.rr.com>
wrote:

> Hello,
>
> I'm trying to show a circle in a vector field in R^3.
>
> Here's my vector field:
>
> vectorfield01 = VectorPlot3D[{y, -x, 0}, {x, -2, 2}, {y, -2, 2}, {z,
> -2, 2},
>  VectorScale -> 0.1,
>  VectorPoints -> {9, 9, 5}]
>
> Here's my circle:
>
> circle01 = ParametricPlot3D[{Cos[t], Sin[t], 2}, {t, 0, 2 \[Pi]},
>  PlotStyle -> Directive[Thick, Black],
>  PlotRange -> {{-2, 2}, {-2, 2}, {-2, 2}}]
>
> Each of these individually gives me what I want, but when I try
>
> Show[circle01, vectorfield01]
>
> I get the error message
>
> Show::gcomb: Could not combine the graphics objects in Show[\!\(\*
>
> I've tried all kinds of combinations with Graphics3D[ ] etc.
>
> Any help would be appreciated!
>
> Thanks very much,
>
> Randy Scott
> Santiago Canyon College

It should work, and your example does work for me, yielding a vortex
with a black halo, so I don't know what the problem is.

I wonder if you have an invisible but bad character in the Mathematica file.  I
would put the example in a new notebook, manually retyping the Mathematica code,
and see if the problem goes away.

Another dodge is to quit the kernel, use Delete All Output from the Cell