Re: v.6 RevolutionPlot3D
- To: mathgroup at smc.vnet.net
- Subject: [mg75939] Re: [mg75852] v.6 RevolutionPlot3D
- From: Andrzej Kozlowski <akoz at mimuw.edu.pl>
- Date: Sun, 13 May 2007 06:00:46 -0400 (EDT)
- References: <200705120700.DAA23589@smc.vnet.net>
On 12 May 2007, at 16:00, Helen Read wrote:
> We just got 6.0 on our site license, and I installed on my computer(s)
> yesterday.
>
> I see that SurfaceOfRevolution (which was in an add on package) has =
> been
> replaced by RevolutionPlot3D. Sounds great, except that
> RevolutionPlot3D
> only revolves around the vertical axis. We (my calculus students) used
> the old SurfaceOfRevolution all the time for visualizing surfaces of
> revolution for computing volume and surface area, and we need to be =
> able
> to revolve around both the vertical axis and the horizontal axis. This
> was a simple matter of setting RevolutionAxis->{0,0,1} or
> RevolutionAxis->{1,0,0} respectively. Now, I can write a function for
> revolving around the horizontal axis and provide it to the
> students, but
> I can already foresee the confusion it will cause when they can use a
> built-in function for revolving in one direction, and have to do it a
> different way to revolve in the other direction.
>
> --
> Helen Read
> University of Vermont
>
First of all, you can still use SurfaceOfRevolution in Mathematica 6:
<< Graphics`SurfaceOfRevolution`
(ignore the compatibility message)
SurfaceOfRevolution[x^2, {x, 0, 1},
RevolutionAxis -> {1, 1, 1}]
(example taken form te Documentation for 5.2).
You get the same picture as before but now you can do all the new
things that Mathematica 6 graphics allow you to do.
Another possibility is simply to forget about RevolutionPlot3D and
use ParametricPlot3D:
ParametricPlot3D[Evaluate[{X, Y, Z} /. Solve[RotationMatrix[{{1, 1,
1}, {0, 0, 1}}].{X, Y, Z} == {t Cos[=CE=B8], t Sin[=CE=B8], t^2 }, =
{X, Y,
Z}]], {t, 0, 1}, {=CE=B8, 0, 2 =CF=80}]
Andrzej Kozlowski=
- References:
- v.6 RevolutionPlot3D
- From: Helen Read <read@math.uvm.edu>
- v.6 RevolutionPlot3D