[R] Stacked density plots

[David Winsemius]

On Apr 10, 2009, at 4:53 PM, Judith Flores wrote:

>
> Hello R-community,
>
>    I want to generate stacked density plots in lattice. My data  
> consist of a numeric variable ('pid') that is measured in different  
> individuals ('id'), which can be divided in two types ('type') and  
> the measurements were repeated a different time points ('day').
>
> I read in the Lattice book that this can be done using the 'flowViz'  
> package, so I tried to reproduce the example given in there and  
> obtained an error:
>
> library('flowViz')
> data(GvHD, package='flowCore")
> densityplot(Visit~'FSC-H'|Patient, data=GvHD)
>
> Error: ' "FSC-H" ' is/are no valid parameter(s) in this frame
>
>    I am not sure if I am missing something.

You are missing the fact that back-quotes are not the same as single- 
quotes. This should be successful:

densityplot(Visit~`FSC-H`|Patient, data=GvHD)  # rather an attractive  
graph

(You are also posting a question about a Bioconductor package to the  
wrong list. )

> I was hoping to apply something similar to my data, maybe like this?
>
> desityplot(id~pid|type+day, data=mydata)
>
> Thank you in advance for your help,
>

David Winsemius, MD
Heritage Laboratories
West Hartford, CT