[R] print value of variable to screen or alert box?

[David Winsemius]

On May 2, 2009, at 7:59 AM, onyourmark wrote:

>
> I am trying to debug a loop. Is there a way to print the value of a  
> variable
> that is inside a loop? I have a vector v and inside a loop I have  
> v[i] where
> i is the index of the loop. Is there a way to see v[i] per loop so  
> that I
> can see what is going on?
> Thanks
> -- 

 > v <- vector()

 > for (i in 1:5) { v[i] <- i^2; print(v[i])}
[1] 1
[1] 4
[1] 9
[1] 16
[1] 25

 > for (i in 1:5) { v[i] <- i^2; print(paste(i, " squared = ", v[i]))}
[1] "1  squared =  1"
[1] "2  squared =  4"
[1] "3  squared =  9"
[1] "4  squared =  16"
[1] "5  squared =  25"

David Winsemius, MD
Heritage Laboratories
West Hartford, CT