drawing a plot with SEM

I realized after looking again that you asked for plotting. Since you  
only have two points per row, it would be more honest statistically to  
plot the values rather than mean and sem.

 > dm <-read.table(textConnection("      repeat1    repeat2
+ 1        30            34
+ 2        12            23
+ 3         50           13
+ 4         56            98"), header=TRUE)
 > plot(x=1:nrow(dm), y=dm$repeat1, ylim=c(min(dm), max(dm))  )
 > points(x=1:nrow(dm), y=dm$repeat2)

I have a data matrix:
       repeat1    repeat2
1        30            34
2        12            23
3         50           13
4         56            98
.

I would like to plot for the mean and standard error of mean of  
repeat 1 and
repeat2 for each row.
Any pointers on how to do this in R?

TIA,
Anjan
-- 
=============================
anjan purkayastha, phd
bioinformatics analyst
whitehead institute for biomedical research

David Winsemius, MD
Heritage Laboratories
West Hartford, CT