[R] Lattice histogram with vertical lines

[David Scott]

On Tue, 3 Feb 2009, Petr PIKAL wrote:

> Hi
>
> r-help-bounces at r-project.org napsal dne 03.02.2009 09:20:25:
>
>> David Scott <d.scott <at> auckland.ac.nz> writes:
>>
>>>
>>>
>>> I would like to add some vertical lines to a lattice plot of
> histograms.
>>> What I am after is a lattice version of abline(v = 1234). The lattice
>>> histogram plot is just:
>>>
>>> histogram( ~ LTSE | approach, data = arrivals)
>>>
>>
>> As a little variation on the histogram docs example:
>>
>> histogram( ~ height | voice.part, data = singer,
>>           xlab = "Height (inches)", type = "density",
>>           panel = function(x, ...) {
>>               panel.histogram(x, ...)
>>               panel.abline(v= 70)
>>               panel.mathdensity(dmath = dnorm, col = "black",
>>                                 args = list(mean=mean(x),sd=sd(x)))
>>           } )
>>
>>
>
> Or if you want add lines at different places in each panel use this
> function and set once =T
>
> addLine<- function(a=NULL, b=NULL, v = NULL, h = NULL, ..., once=F) {
> tcL <- trellis.currentLayout()
> k<-0
> for(i in 1:nrow(tcL))
>  for(j in 1:ncol(tcL))
>    if (tcL[i,j] > 0) {
> k<-k+1
>        trellis.focus("panel", j, i, highlight = FALSE)
> if (once) panel.abline(a=a[k], b=b[k], v=v[k], h=h[k], ...) else
> panel.abline(a=a, b=b, v=v, h=h, ...)
>        trellis.unfocus()
>        }
> }
>
> Regards
> Petr
>
>

Thanks to all respondents, including the first one who answered my 
question privately, Sundar Dorai-Raj. Sundar's reply was very similar to 
Dieter's version above and worked for me.

I haven't tried Petr's suggestion, but I had been thinking I probably do
need to put different lines on different panels, so this was a nice bit of
anticipation on his behalf

David Scott 
_________________________________________________________________
David Scott	Department of Statistics
 		The University of Auckland, PB 92019
 		Auckland 1142,    NEW ZEALAND
Phone: +64 9 373 7599 ext 85055		Fax: +64 9 373 7018
Email:	d.scott at auckland.ac.nz

Graduate Officer, Department of Statistics
Director of Consulting, Department of Statistics