[R] Problems drawing a colored 'rug' in the Lattice 'densityplot'

[Mark Dalphin]

Thanks Phil,

That is exactly what I was looking for.

Regards,
Mark

Phil Spector wrote:
> 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
>> -- 
>>

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