Re: Two questions
- To: mathgroup@smc.vnet.net
- Subject: [mg11507] Re: [mg11468] Two questions
- From: jpk@max.mpae.gwdg.de
- Date: Fri, 13 Mar 1998 12:21:58 -0500
Hy Selwyn,
> I have two questions that I hope someone can help me with.
>
> 1) Is there a way to use Plot3D to create a ``wireframe" surface
> plot---that is, showing only the grid curves? (No, Shading->False is
> not what I'm after. I want the plot to be _transparent._) If not, is
> there a better way to do it than plotting curves with ParametricPlot3D?
>
Plot3D[] returns a SurfaceGraphics[]-object. The first argument is a
matrix of f(x,y) at the points where the grid is evaluated.
At first You must convert the surface graphics into a ordinary
Graphics3D[] object with Polygon[] primitives. You can do this with
surf=Plot3D[f[x,y],{x,x1,x2},{y,y1,y2}]
gr3d=Graphics3D[surf]
Now You can load the package Graphics`Shapes` it comes with a
WireFrame[] function that does what You want or if You forgot to load
the package You can use the rule
Show[gr3d /. Polygon[pnts_] :> Line[Append[pnts,First[pnts]]]]
> 2) I am continually forgetting to load a package before entering a
> command that it contains. Is there a way to get out of the resulting
> jam without quitting the kernel?
At MathSource in the Enhancements/System folder You will find the
Unshadow package that removes all symbols from the Global context that
is present in other contexts.
Hope that helps
Jens