R help - Dec 2010 - Problems drawing a colored 'rug' in the Lattice 'densityplot'

Hi All,

I'm trying to add a 'rug' representation of my data to a plot
created
with densityplot(). While I can do this in the simple case, I can't do 
it properly when I include the "groups" argument. I have an example 
below. I am running a reasonably new version of R.

print(sessionInfo())
R version 2.12.0 Patched (2010-11-07 r53537)
Platform: i686-pc-linux-gnu (32-bit)

locale:
 [1] LC_CTYPE=en_NZ.UTF-8       LC_NUMERIC=C               LC_TIME=en_NZ.UTF-8  
LC_COLLATE=en_NZ.UTF-8
 [5] LC_MONETARY=C              LC_MESSAGES=en_NZ.UTF-8    LC_PAPER=en_NZ.UTF-8 
LC_NAME=C
 [9] LC_ADDRESS=C               LC_TELEPHONE=C            
LC_MEASUREMENT=en_NZ.UTF-8 LC_IDENTIFICATION=C

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     

other attached packages:
[1] lattice_0.19-13

R code to show the problem:

## Setup - load package, set random seed & create fake dataset
library(lattice)
set.seed(1234)
d <- data.frame(Type=rep(LETTERS[1:4], times=250),
                Category=rep(LETTERS[22:26], times=200),
                Value=c(rnorm(500), rnorm(300, 0.5), rnorm(200, 1))
                )

## Basic "densityplot" using 'points' to show the data
densityplot(~Value|Type, data=d)

## And I can plot a 'rug' for the simple density plot
densityplot(~Value|Type, data=d, plot.points='rug')

## Now add a "groups" selector to show sub-grouping of data by
'Category'
## Note: the data points are in color
densityplot(~Value|Type, group=Category, data=d)

## Finally, with the groups, and with a rug.
## Note: no color for the rug
densityplot(~Value|Type, group=Category, data=d, plot.points='rug')


So, I can draw a rug (which is an improvement over version 2.9.1 of R 
when I got no rug), however, the color associated with the 'group' 
doesn't seem to propagate through to the rug. Is there something I am 
doing wrong here or is this a bug? Anyone have suggestions to work 
around this?

Regards,
Mark
--

Mark -
    If I understand what you want, it can be done with a custom
panel function:

mypanel = function(x,subscripts,groups,...){
  
panel.densityplot(x,plot.points=FALSE,groups=groups,subscripts=subscripts,...)
  
panel.rug(x,col=trellis.par.get('superpose.line')$col[groups[subscripts]])
}

Then I think you'll get the result you want if you use

densityplot(~Value|Type, group=Category, data=d, panel=mypanel)

 					- Phil Spector
 					 Statistical Computing Facility
 					 Department of Statistics
 					 UC Berkeley
 					 spector at stat.berkeley.edu

On Thu, 16 Dec 2010, Mark Dalphin wrote:
> Hi All,
>
> I'm trying to add a 'rug' representation of my data to a plot
created with
> densityplot(). While I can do this in the simple case, I can't do it
properly
> when I include the "groups" argument. I have an example below. I
am running a
> reasonably new version of R.
>
> print(sessionInfo())
> R version 2.12.0 Patched (2010-11-07 r53537)
> Platform: i686-pc-linux-gnu (32-bit)
>
> locale:
> [1] LC_CTYPE=en_NZ.UTF-8       LC_NUMERIC=C              
LC_TIME=en_NZ.UTF-8
> LC_COLLATE=en_NZ.UTF-8    [5] LC_MONETARY=C 
> LC_MESSAGES=en_NZ.UTF-8    LC_PAPER=en_NZ.UTF-8       LC_NAME=C 
> [9] LC_ADDRESS=C               LC_TELEPHONE=C 
> LC_MEASUREMENT=en_NZ.UTF-8 LC_IDENTIFICATION=C 
> attached base packages:
> [1] stats     graphics  grDevices utils     datasets  methods   base 
> other attached packages:
> [1] lattice_0.19-13
>
> R code to show the problem:
>
> ## Setup - load package, set random seed & create fake dataset
> library(lattice)
> set.seed(1234)
> d <- data.frame(Type=rep(LETTERS[1:4], times=250),
>               Category=rep(LETTERS[22:26], times=200),
>               Value=c(rnorm(500), rnorm(300, 0.5), rnorm(200, 1))
>               )
>
> ## Basic "densityplot" using 'points' to show the data
> densityplot(~Value|Type, data=d)
>
> ## And I can plot a 'rug' for the simple density plot
> densityplot(~Value|Type, data=d, plot.points='rug')
>
> ## Now add a "groups" selector to show sub-grouping of data by
'Category'
> ## Note: the data points are in color
> densityplot(~Value|Type, group=Category, data=d)
>
> ## Finally, with the groups, and with a rug.
> ## Note: no color for the rug
> densityplot(~Value|Type, group=Category, data=d, plot.points='rug')
>
>
> So, I can draw a rug (which is an improvement over version 2.9.1 of R when
I
> got no rug), however, the color associated with the 'group'
doesn't seem to
> propagate through to the rug. Is there something I am doing wrong here or
is
> this a bug? Anyone have suggestions to work around this?
>
> Regards,
> Mark
> -- 
>