On Thu, Aug 19, 2010 at 4:45 PM, Hall, Ken (CDC/OSELS/NCPHI) <k...@cdc.gov> wrote: > Please let me know if this is or is not the right place to ask these > types of questions. > > Warning: I am new to R by two days. > > I have a simple dataset. > I have loaded the dataset successfully using the following code: > > Filepath=(C:\temp\\pilot\dataset1.txt") > Pilot=read.table(filepath, header=TRUE) > > Dataset1.txt is delimited and looks like this: > > Date illness count > 2006/01/01 derm 17 > 2006/01/01 derm 35 > 2006/01/02 derm 24 > 2006/01/02 derm 80 > . > . > . > Total records like this approximately 18,000 > > I would like to use the aggregate function to sum the count by similar > date and illness, so it should look like this after the aggregate > > 2006/01/01 derm 52 > 2006/01/02 derm 104 > .
Try: aggregate(Pilot[3], Pilot[1:2], sum) or aggregate(count ~., Pilot, sum) ______________________________________________ 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.