Ken - Try aggregate(Pilot$Count,list(Date=Pilot$Date,illness=Pilot$illness),sum)
If you don't want to keep typing "Pilot", use with(Pilot,aggregate(Count,list(Date=Date,illness=illness),sum)) Notice that the aggregated variable will be called "x" in the output data frame from aggregate. - Phil Spector Statistical Computing Facility Department of Statistics UC Berkeley spec...@stat.berkeley.edu On Thu, 19 Aug 2010, Hall, Ken (CDC/OSELS/NCPHI) 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 . . . And, the illness changes to fever with the same pattern. I would like to aggregate the same illnesses by date in the same fashion. A nudge in the right direction would be appreciated. Thanks. Ken Hall Computer Scientist Division of Healthcare Information (DHI) (proposed) Public Health Surveillance Program Office (proposed) Office of Surveillance, Epidemiology, & Laboratory Services (OSELS) (proposed) Centers for Disease Control & Prevention (CDC) k...@cdc.gov Mobile: 404-993-3311 Office: 404-498-6839 [[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.
______________________________________________ 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.