Change your two lines> arrows(xvals, mean, xvals, CI.H, angle=90,length=length)
> arrows(xvals, mean, xvals, CI.L, angle=90,length=length)
to the one line
arrows(xvals, mean, xvals, mean + sign(mean) * se, angle=90,
length=length)
(I would also use a scatter plot instead of a barplot for this sort of thing and
draw both error bars. I think the bars give a misleading impression of what
is going on.)
Bill Dunlap
Spotfire, TIBCO Software
wdunlap tibco.com
> -----Original Message-----
> From: r-help-bounces at r-project.org [mailto:r-help-bounces at
r-project.org] On Behalf
> Of raz
> Sent: Wednesday, November 27, 2013 7:23 AM
> To: r-help at r-project.org
> Subject: [R] Conditional error bars
>
> How can I condition any error bar function that use the arrows() function,
> such as 'CI.plot' (see example below) or 'error.bars', to
draw only upper
> error bar (upper CI) if the bar value (mean) is positive and the lower
> error bar (lower CI) if bar value is negative?
>
> CI.plot <- function(mean, se,length, ylim=c(-5, max(CI.H)), ...) {
> CI.H <- mean+se
> CI.L <- mean-se
> xvals <- barplot(mean, ylim=ylim, ...) # Plot bars
> arrows(xvals, mean, xvals, CI.H, angle=90,length=length)
> arrows(xvals, mean, xvals, CI.L, angle=90,length=length)
> }
>
> CI.plot(D,SE,0.01)
>
> thanks,
> --
> \m/
>
> [[alternative HTML version deleted]]
>
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