[R] stacked histograms

[Arne Schröder]

I want to produce stacked histograms where the total bar is divided up 
according to the n levels of the grouping variable given in the group 
argument.
I am using the lattice histogram function and its "group"-argument, but 
it is not recognised. The "auto.key" argument, however, is, because it 
gives
me the correct group levels and when setting groups = NULL, auto.key = 
TRUE is obviously not producing any legend). Is this because the default 
"panel"-argument of histogram() = panel.histogram has no group-argument 
(in contrast to the xyplot() function and xyplot.histogram)? Is tehre a 
way around it?
Thanks a lot in advance.

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Arne Schröder, PhD student
Department for Ecology and Environmental Science
Umeå University
SE-901 87 Umeå
Sweden

phone: +46 (0)90 786 6635
e-mail: arne.schroder at emg.umu.se
fax: +46 (0)90 786 6705