[R] Vertical line in densityplot?

[Thomas Petzoldt]

Hi,

lattice graphics work by utilizing so called panel functions. Here is a 
working version of your example:

library(lattice)
x<-rnorm(100)
plot.new()
densityplot(x,
   panel=function(x, ...){
     panel.densityplot(x, ...)
     panel.abline(v=0)
   }
)


For mor information, please look into the examples of densityplot and 
the help file of panel.abline


Hope it helps

Thomas


Gustaf Rydevik wrote:
> Hi all,
> 
> I'm trying to get a vertical line at a specific point in a
> densityplot. abline seems to be what's required, but it doesn't align
> itself to the scale used in the plot.
> 
> example:
> 
> library(lattice)
> x<-rnorm(100)
> plot.new()
> densityplot(x)
> abline(v=0)
> -----
> The line seems to use some other coordinate system. What kind of call
> do I use to make abline use the graph's coordinates?
> 
> Additionally, it would be nice to have standard xy-axis, and to have
> the line stop at the x-axis, so if anyone could tell me how to do
> that, I'd be grateful.

What is a "standard x achsis?".

> Thanks in advance,
> 
> Gustaf
> 
> 
> PS: a minor question: Why do I have to call plot.new() for abline to work?
>