El mi?, 20-05-2009 a las 14:26 +0200, C-Sigma escribi?:
> Hi all,
> I am just new on the list with the following puzzle:
>
> trying this (a simple modification of the one at
> http://www.telefonica.net/web2/biomates/maxima/gpdraw/func3d/index.html)
>
> load(draw)$
> draw3d(enhanced3d = true,
> palette = gray,
> meshed_surface = false,
> surface_hide = true,
> explicit(20*exp(-x^2-y^2)-10,x,-3,3,y,-3,3),
> meshed_surface = false,
> explicit(x+y,x,-5,5,y,-5,5)) $
>
> you get exactly the same plot of a plane intersecting a "witch hat".
>
> However:
> - set TRUE the mesh on the witch hat, and FALSE the mesh on the plane
> ==> top half of hat disappears
> - set FALSE the mesh on the witch hat, and FALSE the mesh on the
> plane ==> top half of hat disappears
> - set FALSE the mesh on the witch hat, and TRUE the mesh on the plane
> ==> top half of hat barely visible (plane's mesh does not appear to
> be hidden behind the hat's surface)
> - setting or unsetting surface_hide does not help with the
> disappearing of the top half of the witch hat
>
> Otherwise I find the DRAW interface just great !
>
> Anybody with suggestions ?
>
Ciao Luca, I have bad news.
Option 'meshed_surface' was recently introduced in draw, but as you are
pointing out in your post, it has some problems.
We (Joan Pau and me) have tried to fix these inconsistencies some weeks
ago, but didn't find the way to make options 'meshed_surface' and
'enhanced3d' live together. As a consequence, I decided to remove this
option, both from cvs draw and from the examples in the web site.
With this ugly workaround taken from the web site, you can plot a meshed
surface:
draw3d (user_preamble = "set pm3d at s depthorder",
color = green,
explicit(x^2+y^2, x,-2,2,y,-2,2)) $
Sorry for the inconvenience.
--
Mario