[R] Alignment of lines within barplot bars

[Greg Snow]

Sorry I took so long to get back on this, I have been out of town.

For your case you need to provide adjustments for both the x and y to updateusr, try this:

library(TeachingDemos)
tmp <- barplot(c(1.5,40),yaxt='n',names.arg=1:2,ylim=c(0,1.25*40))
axis(4)
tmp2 <- par('usr')
updateusr(tmp[1:2], tmp2[3:4], 1:2, c(0,0.022) )
points( 1:2, c(0.01, 0.02), pch=16 )
axis(2)


You can make further adjustments to the new y axis by changing the 0.022 in the updateusr call.

-- 
Gregory (Greg) L. Snow Ph.D.
Statistical Data Center
Intermountain Healthcare
greg.snow at imail.org
801.408.8111


> -----Original Message-----
> From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-
> project.org] On Behalf Of snowboarder101
> Sent: Friday, April 08, 2011 2:26 PM
> To: r-help at r-project.org
> Subject: Re: [R] Alignment of lines within barplot bars
> 
> Thanks for the reply. I looked at this before as I saw you had posted
> this,
> but this either doesn't work in my situation, or I am using it wrong.
> 
> Take the example in the function:
> 
> tmp <- barplot(1:4)
> updateusr(tmp[1:2], 0:1, 1:2, 0:1)
> lines(1:4, c(1,3,2,2), lwd=3, type='b',col='red')
> 
> But I want to use par(new=T) and plot(), so:
> 
> tmp <- barplot(1:4)
> par(new=T)
> updateusr(tmp[1:2], 0:1, 1:2, 0:1)
> plot(1:4, c(1,3,2,2), lwd=3, type='b',col='red')
> 
> The reason I do this is that the y-axis then corresponds to my plot()
> data.
> In my specific case, it's more like this:
> 
> tmp <- barplot(c(1.5,40),yaxt='n',names.arg=1:2,ylim=c(0,1.25*40))
> axis(4)
> par(new=T)
> updateusr(tmp[1:2], 1:2)
> plot(1:2,c(0.01,0.02),xaxt='n',pch=16)
> 
> I want those points in the middle of the bars... but I want to keep the
> y-axis labels from the second plot. the par(new=T) probably wipes out
> the
> coordinates, so I'm not sure how use this?
> 
> Thanks Again.
> 
> 
> --
> View this message in context: http://r.789695.n4.nabble.com/Alignment-
> of-lines-within-barplot-bars-tp2533115p3437369.html
> Sent from the R help mailing list archive at Nabble.com.
> 
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