[R] pairewise plots

[Duncan Murdoch]

On Tue, 29 Mar 2005 06:58:51 -0800 (PST), Hai Lin
<kevinvol2002 at yahoo.com> wrote :

>Dear R users,
> 
>I have a data generated as the following,
> 
>dat <- data.frame(matrix(sample(24), nrow=4))
>dimnames(dat) <-list(rownames=c('g1','g2','g3','g4'), colnames=c("A_CH1","A_CH2","B_CH1","B_CH2","C_CH3","C_CH3"))
> 
>» dat
>   A_CH1 A_CH2 B_CH1 B_CH2 C_CH3 C_CH3
>g1    16    24     7     9    14    20
>g2     4    10    19    22     5    17
>g3    11    18    21    12    13     1
>g4     2     3    15     6    23     8
> 
>I am trying to plot them pairwise by column(might extend to more than 3 pairs) 
>Instead manually plotting as below, could you please point me out with easier ways? 
> 
>par(mfrow=c(3,1))
>plot(dat$A_CH1+dat$A_CH2, dat$A_CH1-dat$A_CH2)
>plot(dat$B_CH1+dat$B_CH2, dat$B_CH1-dat$B_CH2)
>plot(dat[,5]+dat[,6], dat[,5]-dat[,6])

Your last line gives the hint:

for (i in 1:3) {
  c1 <- dat[,2*i - 1]
  c2 <- dat[,2*i]
  n1 <- colnames(dat)[2*i - 1]
  n2 <- colnames(dat)[2*i]
  plot(c1+c2, c1-c2, main=paste("Pair", i,":",n1, n2))
}

Duncan Murdoch