R help - Dec 2002 - lattice barchart with "negative" bars

Dear all,

I'm trying to use the lattice barchart function to obtain a bar plot of a 
variable for different values of two factors. The thing I'm trying to do is 
something like this:
> barchart(MyVar ~ season | place, data=mydataset)
My problem is that the column MyVar has some negative values and I would like 
them to be represented as bars stacking down from zero instead of what the 
function does that is finding the minimum value and then stacking all bars 
from this minimum value up. I've looked into the the help pages and I saw no
way to go around this behaviour. Is there an easy way to get these
"negative"
bars?

Thanks,
Luis
 
-- 
Luis Torgo
    FEP/LIACC, University of Porto   Phone : (+351) 22 607 88 30
    Machine Learning Group           Fax   : (+351) 22 600 36 54
    R. Campo Alegre, 823             email : ltorgo at liacc.up.pt
    4150 PORTO   -  PORTUGAL         WWW   : http://www.liacc.up.pt/~ltorgo

On Tuesday 10 December 2002 06:11 am, Luis Torgo wrote:
> Dear all,
>
> I'm trying to use the lattice barchart function to obtain a bar plot of
a
> variable for different values of two factors. The thing I'm trying to
do is
>
> something like this:
> > barchart(MyVar ~ season | place, data=mydataset)
>
> My problem is that the column MyVar has some negative values and I would
> like them to be represented as bars stacking down from zero instead of what
> the function does that is finding the minimum value and then stacking all
> bars from this minimum value up. I've looked into the the help pages
and I
> saw no way to go around this behaviour. Is there an easy way to get these
> "negative" bars?
No, I don't think so (short of using a modified panel.barchart, which should
be relatively easy -- panel.barchart essentially has just 3 lines of code). 
But this seems very reasonable thing to want, so I'll add an option for
this.

You could also use xyplot with type = "h", but that will give you
lines
instead of bars.

Deepayan