[R] [FORGED] About error bars on barplots

[Rolf Turner]

On 18/06/17 12:10, lily li wrote:
> Hi R users,
> 
> I have a question about adding uncertainty bars to stacked bar plots.
> 
> DF:
>    year   A   B   C   Amin  Amax  Bmin  Bmax  Cmin  Cmax
>   2009  40  45  15   30      61       23       56      14       17
>   2010  36  41  23   26      54       22       51      22       24
> 
> I use the code below:
> 
> DF.refm = melt(subset(DF[,c(1:4)]),id.vars='year',variable_name='Legend')
> 
> fig1 = ggplot(data=DF.refm, aes(x=year,y=value,fill=Legend))+
>    geom_bar(stat='identity',size=.5)+ theme_bw()+ xlab('Year')+
> ylab('Percent (%)')
> print(fig1)
> 
> But I don't know how to change it a little bit. For example, how to add the
> error bars on the plot, as is shown in the figure below? The error bar for
> variable A ranges from Amin to Amax, the same applies to variables B and C.
> Thanks for your help.


Your figure did not come through, at least not to me.  You are probably 
doing something fancy, and the mailing list software stripped out the 
figure.  *Do* learn to keep things simple.  _Attach_ figures as *.pdf 
files, for instance.

That being said, to answer your question, my advice (and that of many 
others) is: DON'T.  Error bars on boxplots (such plots are sometimes 
known as "dynamite plots" or "detonator plots") are considered by the 
cognoscenti to be abominations.

cheers,

Rolf

-- 
Technical Editor ANZJS
Department of Statistics
University of Auckland
Phone: +64-9-373-7599 ext. 88276