I am having trouble doing the following. I have a data.frame like this, where x and y are a variable that I want to do calculations on:
Name Year x y ab 2001 15 3 ab 2001 10 2 ab 2002 12 8 ab 2003 7 10 dv 2002 10 15 dv 2002 3 2 dv 2003 1 15 Before I do all the other things I need to do with this data, I need to summarize or collapse the data by name and year. I've found that I can do things like nameyear<-interaction(name,year) dataframe$nameyear<-nameyear tapply(dataframe$x,dataframe$nameyear,sum) tapply(dataframe$y,dataframe$nameyear,sum) and then bind those together. But my problem is that I need to somehow retain the original Names in my collapsed dataset, so that later I can do analyses with the Name factors. All I can think of is something like tapply(dataframe$Name,dataframe$nameyear, somefunction?) but nothing seems to work. I'm actually trying to convert a SAS program, and I can't get out of that mindset. There, it's a simple Proc Means, By Name Year. Thanks for any help or suggestions on the right way to go about this. Matt Crawford ______________________________________________ [email protected] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
