[R] How to put line linking two plots

[Greg Snow]

Here is a way to do it using just base graphics:

layout(matrix(c(1,1,2,3), 2, 2, byrow = TRUE))
plot(runif(10), type='b', ylim=c(0,1))
x.tmp <- grconvertX(4, to='ndc')
y.tmp <- grconvertY(0.9, to='ndc')
plot(runif(20), type='l', ylim=c(0,1))
par(xpd=NA)
segments( 10, 1,
 grconvertX(x.tmp,  from='ndc'), grconvertY(y.tmp, from='ndc'),
	col='red' )
plot(runif(20), type='l')



-- 
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 Paul Murrell
> Sent: Wednesday, March 30, 2011 4:29 PM
> To: Mario Valle
> Cc: R-help at r-project.org
> Subject: Re: [R] How to put line linking two plots
> 
> Hi
> 
> On 30/03/2011 10:54 p.m., Mario Valle wrote:
> > Hello!
> > Suppose I have three charts like below. The top chart is a general
> > overview and the bottom charts are related so some point of this
> chart.
> > To make clear this relationship I want to draw a line between (4,0.9)
> in
> > the top chart and (10,1) in the bottom-left one.
> > Currently I add it manually using Inkscape on the resulting pdf file.
> > Is it possible to add it inside R? Should I switch to other charting
> > packages?
> 
> You'll have your work cut out using traditional graphics, but this is
> doable in grid-based graphics.  For example, ...
> 
> library(grid)
> library(lattice)
> 
> set.seed(123)
> print(xyplot(runif(10)~1:10, type="b"),
> 	position=c(0, .5, 1, 1),
> 	prefix="top",
> 	more=TRUE)
> print(xyplot(runif(20)~1:20, type="l"),
> 	position=c(0, 0, .5, .5),
> 	prefix="left",
> 	more=TRUE)
> print(xyplot(runif(20)~1:20, type="l"),
> 	position=c(.5, 0, 1, .5),
> 	prefix="right")
> trellis.focus("panel", 1, 1, prefix="top")
> grid.move.to(unit(4, "native"), unit(.9, "native"))
> trellis.unfocus()
> trellis.focus("panel", 1, 1, prefix="left", clip.off=TRUE)
> grid.line.to(unit(10, "native"), unit(1, "native"))
> trellis.unfocus()
> 
> Paul
> 
> > Thanks for the advice!
> >                                                   mario
> >
> > set.seed(123)
> > pdf("test.pdf", width=14, height=7)
> > layout(matrix(c(1,1,2,3), 2, 2, byrow = TRUE))
> > plot(runif(10), type='b')
> > plot(runif(20), type='l')
> > plot(runif(20), type='l')
> > dev.off()
> >
> > R 2.12.2 on Windows 7 (32bits)
> >
> 
> --
> Dr Paul Murrell
> Department of Statistics
> The University of Auckland
> Private Bag 92019
> Auckland
> New Zealand
> 64 9 3737599 x85392
> paul at stat.auckland.ac.nz
> http://www.stat.auckland.ac.nz/~paul/
> 
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