[R] two connected graphs

[John Kane]

--- Robin Hankin <r.hankin at noc.soton.ac.uk> wrote:

> Hi
> 
> I have two datasets, A and B, consisting of two
> columns of numbers
> representing x and y coordinates.
> 
> They have 10 and 6 rows respectively.
> 
> I want to plot two scattergraphs, one above the
> other.
> 
> The lower graph to contain A (10 points) and the
> upper
> graph to contain B (six points).
> 
> The x-axes of the two graphs must line up.
> 
> I then want to draw straight lines that connect
> points
> of  B to a particular point (or points)  of A.
> 
> How do I do this?

?par and read up on mfrow for the two graphs.


Here is something that may help for the lines
http://finzi.psych.upenn.edu/R/Rhelp02a/archive/1926.html

The code below will  work but I had to figure out the
arrow coordinates by trial and error and there must be
a better way.

aa <- c(1:10)
bb <- c(1:6)
op <- par(mfrow = c(2,1), oma=c(1,0,3,0), las=1, xpd =
NA )
plot(aa)
plot(bb)
arrows( 3,3, 4.9, 21.5, length=0)