R help - Nov 2004 - 3d scatter plot with drop line

This is a follow up to my question from yesterday. I want to do in R
what is called a "3d scatter plot with drop lines" in S-PLUS.

Basically, it's a 3dscatterplot with lines connecting the x-y grid to
the z points.
The lines give a better perspective on the shape of the data surface.

How to?

Joel Bremson
UC Davis Statistics

On Wed, 17 Nov 2004 12:03:54 -0800, Joel Bremson <joel3000 at gmail.com>
wrote :
>This is a follow up to my question from yesterday. I want to do in R
>what is called a "3d scatter plot with drop lines" in S-PLUS.
>
>Basically, it's a 3dscatterplot with lines connecting the x-y grid to
>the z points.
>The lines give a better perspective on the shape of the data surface.
>
>How to?
The scatterplot3d package does this in one of its examples, using
type='h'.

Duncan Murdoch

On Wednesday 17 November 2004 14:03, Joel Bremson wrote:
> This is a follow up to my question from yesterday. I want to do in R
> what is called a "3d scatter plot with drop lines" in S-PLUS.
>
> Basically, it's a 3dscatterplot with lines connecting the x-y grid to
> the z points.
> The lines give a better perspective on the shape of the data surface.
>
> How to?
One possibility would be 

library(lattice)
cloud(y ~ x * z, type = 'h')

This actually tries to drop the lines to the X-Y plane (z = 0) (which is 
truncated on the 'x-y grid' if the z-limits don't include 0).

Deepayan

Very nice!
I noticed that you wrote the function to drop points to any surface.
Is it possible to add the surface to the plot as a translucent surface,
so the points and drop lines still show?

David L. Reiner

-----Original Message-----
From: Robin Hankin [mailto:rksh at soc.soton.ac.uk] 
Sent: Thursday, November 18, 2004 3:39 AM
To: joel30000 at gmail.com
Cc: r-help at stat.math.ethz.ch
Subject: Fwd: Re: [R] 3d scatter plot with drop line



Hi

try this:




p3dpairs <- function(x,x1, 
xlim=NULL,ylim=NULL,zlim=NULL,col=par("col"),
pch=par("pch"),
cex=par("cex"), ...){
   if(is.matrix(x)){
     z <- x[,3]
     y <- x[,2]
     x <- x[,1]
   }

     if(is.matrix(x1)){
     z1 <- x1[,3]
     y1 <- x1[,2]
     x1 <- x1[,1]
   }

   if(missing(zlim)) {
     z.grid <- matrix(range(z),2,2)
   } else {
     z.grid <- matrix(zlim,2,2)
   }

   if(missing(xlim)){ xlim <- range(x) }
   if(missing(ylim)){ ylim <- range(y) }

   persp(xlim, ylim, z.grid, col = NA, border=NA, ...) -> res

   trans3d <- function(x,y,z, pmat) {
     tr <- cbind(x,y,z,1) %*% pmat
     list(x = tr[,1]/tr[,4], y= tr[,2]/tr[,4])
   }

   out <- trans3d(x,y,z,pm=res)
   out1 <- trans3d(x1,y1,z1,pm=res)
   points(out, col=col, pch=pch, cex=cex, ...)

   for(i in 1:length(out$x)){
     lines(c(out$x[i],out1$x[i]),c(out$y[i],out1$y[i]), col="gray",
...)
   }
   return(invisible(out))
}




then


a <- matrix(rnorm(60),20,3)
  b <- a
b[,3] <- 0
  p3dpairs(a,b)


gives you a good approximation to what you want

HTH

rksh
>
>
>>This is a follow up to my question from yesterday. I want to do in R
>>what is called a "3d scatter plot with drop lines" in S-PLUS.
>>
>>Basically, it's a 3dscatterplot with lines connecting the x-y grid
to
>>the z points.
>>The lines give a better perspective on the shape of the data surface.
>>
>>How to?
>>
>>Joel Bremson
>>UC Davis Statistics
>>
>>______________________________________________
>>R-help at stat.math.ethz.ch mailing list
>>https://stat.ethz.ch/mailman/listinfo/r-help
>>PLEASE do read the posting guide!
http://www.R-project.org/posting-guide.html
>
>
>--
>
>Robin Hankin
>Uncertainty Analyst
>Southampton Oceanography Centre
>SO14 3ZH
>tel +44(0)23-8059-7743
>initialDOTsurname at soc.soton.ac.uk (edit in obvious way; spam
precaution)


-- 
Robin Hankin
Uncertainty Analyst
Southampton Oceanography Centre
SO14 3ZH
tel +44(0)23-8059-7743
initialDOTsurname at soc.soton.ac.uk (edit in obvious way; spam precaution)
	[[alternative HTML version deleted]]

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