[R] SOLVED: Lattice: How to do error bars

[amvds at xs4all.nl]

Thank you Gerrit,

Your suggestion proved right after all:

This does put error bars (dy) on the points. You only need to figure out
the proper y axis scaling.

> xyplot(y~x|f,data=xy,groups=dy,panel=function(x,y,groups,subscripts,...)
{panel.xyplot(x,y,...)
;panel.segments(x,y+groups[subscripts],x,y-groups[subscripts],...)})

Regards,
Alex van der Spek

> Hello, Alex,
>
> not sure in this case, but I think you have to provide and use an argument
> named "subscripts" for the panel function. See ?xyplot.
>
>
> On Tue, 11 Aug 2009, Alex van der Spek wrote:
>
>> I am trying to add 2 stdev error bars to lattice type plots:
>>
>> panel.ebar<-function(x,y,dy=NULL,...) {
>> 	panel.xyplot(x,y,...)
>> 	panel.segments(x,y-dy,x,y+dy,...)
>> }
>>
>> Then:
>>
>> xyplot(y~x|fc,data=dat,dy=dat$dy,panel=panel.ebar)
>>
>> This adds error bars but they are not conditioned on the factor fc.
>>
>> xyplot(y+I(y-dy)+I(y+dy)~x|fc,data=dat)
>>
>> This produces 3 series of points in different colors, conditioned on fc
>> as the data is now grouped per panel.
>>
>> Obviously I need a combination of the above two. I can't figure it out.
>>
>> Any help? Just point to docs if avaiable. The R doc is excellent. Most
>> of the time I can save myself.
>>
>> Thanks in advance!
>> Alex van der Spek
>>
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>> and provide commented, minimal, self-contained, reproducible code.
>>
>
>   Regards  --  Gerrit
>
> ---------------------------------------------------------------------
> AOR Dr. Gerrit Eichner             Mathematical Institute, Room 305 E
> gerrit.eichner at math.uni-giessen.de   Justus-Liebig-University Giessen
> Tel: +49-(0)641-99-32104          Arndtstr. 2, 35392 Giessen, Germany
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