[R] How to insert gridlines in lattice density plot

[David Winsemius]

On Apr 22, 2010, at 4:52 PM, Bert Gunter wrote:

> " Must one compose a panel function?"
>
> Depending on what you want exactly, no. Add the argument
>
> type="g"
>
> to your call.
> (e.g.
>   densityplot(~fallrates,  groups = prepost,type="g",...
> )
>
> See ?panel.xyplot  and recall that lattice passes down arguments  
> that it
> does not know what to do with to the panel function.

I found that type="g" interfered with execution of the ,,,  
plot.points=TRUE, ... directive and got better success with  ... ,  
type=c("p", "g")

-- 
David.
>
> Bert Gunter
> Genentech Nonclinical Biostatistics
>
>
> -----Original Message-----
> From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org 
> ] On
> Behalf Of Giles
> Sent: Thursday, April 22, 2010 1:31 PM
> To: r-help at r-project.org
> Subject: [R] How to insert gridlines in lattice density plot
>
> Greetings.
>
> How can I  insert gridlines
> in the following density plot call?
> Must one compose a panel function?
>
> 'data.frame':   46 obs. of  2 variables:
>  $ fallrates: num  5.2 7.1 7.1 9.8 3.7 7.5 5 6.2 1.5 2.9 ...
>  $ prepost  : Factor w/ 2 levels "post","pre": 2 2 2 2 2 2 2 2 2 2 ...
>
> library(lattice)
>
>   densityplot(~fallrates,  groups = prepost,
>      kernal="triangular", lwd=2,
>      plot.points = TRUE, ref = TRUE, auto.key = list(columns = 2),
>      main="Estimated fall rate density, pre and post intevention")
>
>
> Thank you for your consideration and comments.
> Giles Crane
>
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.

David Winsemius, MD
West Hartford, CT