[R] interrupted Y axis

[Jim Lemon]

Nick Drew wrote:
> I did not find an answer to my question after a quick
> search using the R
> search engine so thought I'd ask away:
> 
> Does any know if there's a function exists to create
> an interrupted Y axis?
> What I mean by interrupted Y axis is that part of the
> Y axis has been
> removed or excised to permit one to see parts of the
> data in more detail.
> 
> Perhaps an example will make this clear. Please go to
> http://www.jbc.org/cgi/reprint/274/41/28950 and open
> the PDF document
> located there. Go to page 4, figure 2c provides a
> crude example of what I
> mean by interrupted Y axis. Part of the Y axis between
> 800 and 4500 has been
> removed to permit easy inspection of the upper end of
> the range of data.
> (This is not my work but simply an example of what I'm
> trying to describe.)
> One finds these interrupted Y axis graphs in
> newspapers or other
> periodicals, more often than not as a bar chart.
> 
> Does a function in R exist to permit on to this easily
> to a graph? If not,
> would such a function be useful? If yes, would the
> grid package be the right
> tool for me to try and implement this?
> ~Nick
> 
As Gabor and Mark have already pointed out, axis.break() in the plotrix 
package will do the axis break. You will also have to create custom axis 
labels using axis(). However, the plotting function used in the paper 
you cite also breaks the bars that extend to the upper range (nice 
touch, wish I had thought of that). I'm not sure if any of the barplot* 
functions will do this out of the box. I would probably fake the bottom 
and top sections with homemade bars using rect() if I had this problem. 
Anybody have a better idea?

Jim