
Re: dark halo around gaussian peak in Plot3D?
Posted:
Mar 9, 2013 5:26 AM


Michael,
It looks to me like a numeric problem with very small numbers. You can work around it by clipping the function. Here I also scaled up the function by 100 just to get a convenient range.
Plot3D[100 Clip[ PDF[BinormalDistribution[0], {x, y}], {10^150, 20}], {x, 40, 40}, {y, 40, 40}, PlotRange > All, PlotPoints > 30, Mesh > None]
If you decrease the lower Clip value by much you will get the "dark halo" back. It seems to be associated with the front FaceForm losing its color.
Plot3D[100 Clip[ PDF[BinormalDistribution[0], {x, y}], {10^200, 20}], {x, 40, 40}, {y, 40, 40}, PlotStyle > Directive[FaceForm[Gray, Red]], PlotRange > All, PlotPoints > 30, Lighting > "Neutral", Mesh > None]
David Park djmpark@comcast.net http://home.comcast.net/~djmpark/index.html
From: Michael B. Heaney [mailto:mheaney@alum.mit.edu]
Here is simple example that demonstrates the problem:
Plot3D[PDF[BinormalDistribution[0], {x, y}], {x, 40, 40}, {y, 40, 40},
PlotRange > All, PlotPoints > 200]
Thanks,
Michael
On Thu, Mar 7, 2013 at 8:49 PM, Bob Hanlon <hanlonr357@gmail.com> wrote:
> I don't see a "dark halo" with the following > > Plot3D[ > PDF[BinormalDistribution[0], {x, y}], {x, 3, 3}, {y, 3, 3}] > > Can you send a simple example that demonstrates the problem? > > > Bob Hanlon > > > On Thu, Mar 7, 2013 at 10:51 PM, Michael B. Heaney > <mheaney@alum.mit.edu> > wrote: > > > > Hi, > > > > When I plot a gaussian peak in Plot3D, there is a dark halo around > > the peak. Why is this? How can I get rid of it? > > > > Thanks, > > > > Michael > > > >  > >  > > Michael B. Heaney > > 3182 Stelling Drive > > Palo Alto, CA 94303 USA > > mheaney@alum.mit.edu > > www.linkedin.com/in/michaelbheaney > >  > > > > >
  Michael B. Heaney 3182 Stelling Drive Palo Alto, CA 94303 USA mheaney@alum.mit.edu www.linkedin.com/in/michaelbheaney 

