>>>>> "FEH" == Frank E Harrell <[EMAIL PROTECTED]>
>>>>> on Sat, 06 Sep 2008 07:19:33 -0500 writes:
FEH> Brown, Heidi wrote:
>> Hi im trying to add error bars to my barplots, there very basic, i have
a few grapghs where the y variable is different but on all the X variable is
Age (Adult and Juvenile) however this is split into two levels so i have males
and females, so my graph basically has four bars on it.
>>
>> I know how to add eror bars for instance when there is only one level eg
lookng at the diffrence between male and female lizards and tree height and
have used the code:
>>
>> error.bars<-function(yv,z,nn) {
>> xv<-
>>
barplot(yv,ylim=c(0,(max(yv)+max(z))),names=nn,ylab=deparse(substitute(yv)
>> ))
[ omitting the abomination ]
>> Have then worked out the standard errors and added that using:
>>
>> se<-c()
>>
>> and then added the final bit of code:
>>
>> labels<-as.character(levels(Sex2))
>> ybar<-as.vector(tapply(Height2,Sex2,mean))
>> error.bars(ybar,se,labels)
>>
>> So i was wondering, in order to get error bars on my barplot with two
levels do i need to change the last bit of code. For example im looking at mean
body condition (y) against age (x) and sex (level), i tried to change the code
to the following but it didnt work, any suggestions?
>>
>> labels<-as.character(levels(list(sex,Age)))
>> ybar<-as.vector(tapply(ConditionIndex,sex,Age,mean))
>> error.bars(ybar,se,labels)
FEH> See http://biostat.mc.vanderbilt.edu/DynamitePlots for many reasons
not
FEH> to use dynamite plots.
Ah! Very good! Let's hope this eventually leads to progress
i.e., to much less use of these..
Thank you, Frank!
Martin Maechler, ETH Zurich
FEH> --
FEH> Frank E Harrell Jr Professor and Chair School of Medicine
FEH> Department of Biostatistics Vanderbilt University
FEH> ______________________________________________
FEH> R-help@r-project.org mailing list
FEH> https://stat.ethz.ch/mailman/listinfo/r-help
FEH> PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
FEH> and provide commented, minimal, self-contained, reproducible code.
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