R help - Apr 2004 - Adding regression surface to cloud plot

Hello!
I would like to add a plot of the regression surface to my cloud plot . Is it
possible?
Thanks

Anne
	[[alternative HTML version deleted]]

Dear Anne,

You can make such plots with the rgl package. You'll find an example at
<http://socserv.socsci.mcmaster.ca/jfox/Courses/S-course/index.html>.

I hope this helps,
 John 
> -----Original Message-----
> From: r-help-bounces at stat.math.ethz.ch 
> [mailto:r-help-bounces at stat.math.ethz.ch] On Behalf Of Anne
> Sent: Monday, April 26, 2004 8:15 AM
> To: R list
> Subject: [R] Adding regression surface to cloud plot 
> 
> Hello!
> I would like to add a plot of the regression surface to my 
> cloud plot . Is it possible? 
> Thanks
> 
> Anne

Dear Anne,

I should have mentioned that the Rcmdr package contains a function --
scatter3D -- to make these kinds of graphs. (I'm copying this response to
the r-help list -- I hope that's OK.)

John 
> -----Original Message-----
> From: Anne [mailto:anne.piotet at urbanet.ch] 
> Sent: Tuesday, April 27, 2004 1:45 AM
> To: John Fox
> Subject: Re: [R] Adding regression surface to cloud plot 
> 
> Thanks I 'll try
> Anne
> ----- Original Message -----
> From: "John Fox" <jfox at mcmaster.ca>
> To: "'Anne'" <anne.piotet at urbanet.ch>
> Cc: "'R list'" <r-help at stat.math.ethz.ch>
> Sent: Monday, April 26, 2004 3:57 PM
> Subject: RE: [R] Adding regression surface to cloud plot 
> 
> 
> > Dear Anne,
> > 
> > You can make such plots with the rgl package. You'll find 
> an example 
> > at 
> <http://socserv.socsci.mcmaster.ca/jfox/Courses/S-course/index.html>.
> > 
> > I hope this helps,
> >  John
> > 
> > > -----Original Message-----
> > > From: r-help-bounces at stat.math.ethz.ch 
> > > [mailto:r-help-bounces at stat.math.ethz.ch] On Behalf Of Anne
> > > Sent: Monday, April 26, 2004 8:15 AM
> > > To: R list
> > > Subject: [R] Adding regression surface to cloud plot
> > > 
> > > Hello!
> > > I would like to add a plot of the regression surface to my cloud 
> > > plot . Is it possible?
> > > Thanks
> > > 
> > > Anne
> > 
>

On Monday 26 April 2004 08:14, Anne wrote:
> Hello!
> I would like to add a plot of the regression surface to my cloud plot
> . Is it possible? Thanks
Possible (since 1.9.0), but not easy. Technically, the biggest problem 
is deciding which points are 'behind' the surface and which 'in 
front' (that would decide the order of plotting). Otherwise, all the 
pieces are in place.

The following should work for regression surfaces, but may need an 
inequality to be changed for specific viewpoints:


panel.3dreg <-
    function(x, y, z, rot.mat, distance,
             xlim.scaled, ylim.scaled, 
             nmesh = 21, ...)
{
    fm <- lm(z ~ x + y)
    id <- predict(fm) < z ## may need to be reversed
    panel.3dscatter(x[id], y[id], z[id], rot.mat, distance,
                    xlim.scaled = xlim.scaled,
                    ylim.scaled = ylim.scaled,
                    ...)
    x.locs <- seq(xlim.scaled[1], xlim.scaled[2], length = nmesh)
    y.locs <- seq(ylim.scaled[1], ylim.scaled[2], length = nmesh)
    grid <-
        expand.grid(y = y.locs, x = x.locs)
    grid$z <- predict(fm, newdata = grid)
    panel.3dwire(x = x.locs, y = y.locs, z = grid$z,
                 rot.mat, distance,
                 xlim.scaled = xlim.scaled,
                 ylim.scaled = ylim.scaled,
                 ..., col.at = .5, col.regions = "transparent")
    panel.3dscatter(x[!id], y[!id], z[!id], rot.mat, distance,
                    xlim.scaled = xlim.scaled,
                    ylim.scaled = ylim.scaled,
                    ...)
}

## example
data(rock)
cloud(area ~ peri * shape, rock,
      panel.3d.cloud = panel.3dreg,
      nmesh = 40, pch = 16)


- Deepayan