Groups in histograms?

Hi Gary,

I have found this, but it is not exactly what I am looking for.
What I need is the groups to be inside of a single panel, not in
different panels.
Kind of like an histogram version of the xyplot(Y ~ X1,
groups=X2,panel=panel.superpose) command. (I hope this is correct).

/Fredrik

On 8/8/05, Gary Collins <collins.gs at gmail.com> wrote:

Have a look at the "histogram" function in the Lattice package.

if x are your data to be displayed and y is your grouping variable you
can just do

histogram(~x|y)

HTH
Gary

On 08/08/05, Fredrik Karlsson <dargosch at gmail.com> wrote:

Dear list,

I would like to create histograms for up to three groups, with
distincive colour/pattern, in a trellis panel. However, I have not
been able to find a way to do this. histogram does not seem to have a
group argument.

Please help.

/Fredrik

Dear list,

Sorry for answering my own post, but I have had partial sucess in
this. With the panel function below, I get separate histograms in each
panel using the group argument.

histogram(~vot | agem, nint=50,data=work,groups=Type, subset=agem > 24
& agem < 30, panel=panel.grouphist,type="count",ylim=c(0,20),auto.key=T)

panel.grouphist <- function(x,groups,...){
  add <- T
  grouplevels <- unique(groups)
  ngroups <- length(grouplevels)

  for(i in 1:ngroups){
    gcol <- trellis.par.get("superpose.fill")$col[i]
    gx <- x[groups == grouplevels[i]]
    panel.histogram(gx,col=gcol,...)
  }

}

However, the color I get in the key using simpleKey is not the same as
the one in the the plot.
How do I get the two functions to use the same color scale?