[R] How can I return rows from a data frame with maximum value by factor?

[Greg Snow]

For future reference you may want to look at the plyr package, or even the sapply and aggregate functions and possibly simpler ways to do what you did below.

-- 
Gregory (Greg) L. Snow Ph.D.
Statistical Data Center
Intermountain Healthcare
greg.snow at imail.org
801.408.8111


> -----Original Message-----
> From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-
> project.org] On Behalf Of Nick Ackerman
> Sent: Wednesday, March 17, 2010 11:45 AM
> To: r-help at r-project.org
> Subject: Re: [R] How can I return rows from a data frame with maximum
> value by factor?
> 
> 
> Solved my own question by looking at some other threads. For those who
> may be
> intersted, here was the solution to my problem.
> 
> do.call(rbind,lapply(split(data.frame,FISH_ID),function(x)x[which.max(x
> $DATE_TIME),]))
> --
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> tp1596777p1596853.html
> Sent from the R help mailing list archive at Nabble.com.
> 
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