Wow. That was fast -- and spot on!
Thanks so much. Best Regards, Shaun On Aug 26, 2009, at 9:11 AM, Henrique Dallazuanna wrote: > Try this: > > with(d, tapply(count, list(Date, class), sum)) > > On Wed, Aug 26, 2009 at 10:07 AM, Shaun Grannis <sgran...@regenstrief.org > > wrote: > Hi, > > I'm sure there's an easy approach to this issue, I'm just not seeing > it. > > I have a data frame of the following form: > > Date class subclass count > 8/1/2009 A X 1 > 8/1/2009 B X 2 > 8/1/2009 A Y 9 > 8/1/2009 B Y 3 > 8/2/2009 A X 1 > 8/2/2009 B X 5 > 8/2/2009 A Y 4 > 8/2/2009 B Y 2 > 8/3/2009 A X 6 > 8/3/2009 B X 4 > 8/3/2009 A Y 3 > 8/3/2009 B Y 4 > 8/4/2009 A X 1 > 8/4/2009 B X 9 > 8/4/2009 A Y 3 > 8/4/2009 B Y 5 > 8/5/2009 A X 3 > 8/5/2009 B X 7 > 8/5/2009 A Y 2 > 8/5/2009 B Y 1 > > I would like to create a data frame of the sum the daily counts for, > say, class 'A', like so: > > > Date sum_of_counts > 8/1/2009 10 > 8/2/2009 5 > 8/3/2009 9 > 8/4/2009 4 > 8/5/2009 5 > > I ultimately would like to do sum of counts on all classes and > subclasses. It seems that this is equivalent to a GROUP BY query in > SQL. > > I'm sure this is possible in R. Any suggestions? > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. > > > > -- > Henrique Dallazuanna > Curitiba-Paraná-Brasil > 25° 25' 40" S 49° 16' 22" O [[alternative HTML version deleted]]
______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
