Re: [R] Max within groups

2011-07-16 Thread David Winsemius
On Jul 16, 2011, at 9:55 AM, Thomas Chesney wrote: I know there's a really easy way to do this but I just can't track it down. I experimented with various apply functions but couldn't get it quite right. I have a matrix like this: 1, 16 1, 23 1, 21 1, 6 1, 25 2, 4 2, 17 2, 45 2, 11 2, 20

[R] Max within groups

2011-07-16 Thread Thomas Chesney
I know there's a really easy way to do this but I just can't track it down. I experimented with various apply functions but couldn't get it quite right. I have a matrix like this: 1, 16 1, 23 1, 21 1, 6 1, 25 2, 4 2, 17 2, 45 2, 11 2, 20 and I'd like to find the max value in Column 2 (or the in