From: Marc Schwartz (via MN) <mschwartz_at_mn.rr.com>

Date: Sat 08 Jul 2006 - 02:08:49 EST

R-help@stat.math.ethz.ch mailing list

https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html Received on Sat Jul 08 02:16:24 2006

Date: Sat 08 Jul 2006 - 02:08:49 EST

On Fri, 2006-07-07 at 11:47 -0400, Lu, Jiang Jane wrote:

*> Hi,
**>
*

> I am trying to plot odds ratios and the corresponding confidence

*> intervals in horizontal segments. It would be ideal if the confidence
**> interval segment can be drawn with little vertical bars at both ends. I
**> have tried very hard to change the type of ends by using 'lend'
**> arguments, but cannot make it. I even tried 'arrows()', but still
**> failed. Following is the code I use:
**> ====================================================
**> drug.or <- c(1.017,1.437,1.427,2.211)
**> drug.orl <- c(0.715,1.075,1.103,1.696)
**> drug.oru <- c(1.446,1.922,1.845,2.882)
**>
**> yaxis <- seq(1,4,by=1)
**>
**> plot(x=drug.or,y=yaxis,type='p',pch=17,xlim=c(0,3),axes=FALSE,
**> xlab='Odds Ratio',ylab='',main='Reference Group: A only')
**> axis(1,at=seq(0,3,by=0.5),labels=paste(seq(0,3,by=0.5)))
**> axis(2,at=yaxis,las=2)
**>
**>
**> segments(x0=drug.orl,x1=drug.oru,y0=yaxis,y1=yaxis,col=4,lend=2)
**>
**> # or try
**> #arrows(x0=drug.orl,x1=drug.oru,y0=yaxis,y1=yaxis,length=0.1,angle=0,cod
**> e=3,col=4,lend=2)
**>
**> box()
**> =====================================================
*

Try this using arrows():

drug.or <- c(1.017,1.437,1.427,2.211) drug.orl <- c(0.715,1.075,1.103,1.696) drug.oru <- c(1.446,1.922,1.845,2.882)

yaxis <- seq(1, 4, by=1)

plot(drug.or, yaxis ,type='p', pch=17, xlim=c(0,3), axes=FALSE,

xlab='Odds Ratio', ylab='', main='Reference Group: A only')

axis(1, at=seq(0,3,by=0.5), labels=paste(seq(0,3,by=0.5))) axis(2, at=yaxis, las=2)

arrows(drug.orl, yaxis, drug.oru, yaxis, angle=90,

length=0.1, code=3, col=4, lend=2)

You need to specify an angle of 90 degrees to get the arrow heads to be perpendicular to the primary line segment. An angle of 0 superimposes the heads on the primary line segment, so they don't show.

**HTH,
**
Marc Schwartz

R-help@stat.math.ethz.ch mailing list

https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html Received on Sat Jul 08 02:16:24 2006

Archive maintained by Robert King, hosted by
the discipline of
statistics at the
University of Newcastle,
Australia.

Archive generated by hypermail 2.1.8, at Sat 08 Jul 2006 - 04:15:22 EST.

*
Mailing list information is available at https://stat.ethz.ch/mailman/listinfo/r-help.
Please read the posting
guide before posting to the list.
*