Lines dividing graphs using layout() in R

Question

I'm using layout() in R to produce a series of 9 graphs (in a 3x3 layout)

    m <- rbind(c(1,2,3), c(4,5,6), c(7,8,9))
    layout(m)

I'm trying to put 2 vertical lines between the three columns in order to separate the columns from each other. box() is not appropriate as I want the rows to be linked and so don't want lines there, and I'm struggling to find any help using line() function and any ideas would be appreciated.

Thanks

Answer 1

What if you change the graphical parameters so that all plotting is clipped to the device region, and then add the vertical lines for separation afterwards using abline()? For example:

m <- rbind(c(1,2,3), c(4,5,6), c(7,8,9))

# Clips drawing to the device region
# See ?par for more details of the argument
par(xpd=NA)

layout(m)

# Insert you nine plots here
for(i in 1:9) {
   plot(1,1)
}

# Check the correct coordinates with
# locator(), and the arguments
# accordingly. These are about right,
# if the plot region is rectangular.
abline(v=0.25)
abline(v=-1.06)

The resulting plot whould appear as below.

Answer 2

Anothe option is to play with layout:

layout(rbind(c(1,10, 2,11,3),
             c(4,10, 5,11,6),
             c(7,10, 8,11,9)),
widths=c(1, lcm(3), 1,lcm(3),1),
respect=TRUE)

## you plot your 9 plots  
for(i in 1:9) {
  plot(1,1)
}
## you plot the separation 
plot(1,1,type='n',axes=FALSE, ann=FALSE)
## here I use a vertical line but you can plot anything (box, segments,..)
abline(v=1)

plot(1,1,type='n',axes=FALSE, ann=FALSE)
abline(v=1)