I have a data frame called test shown below that i would like to summarize in a particular way :
I want to show the column sums (columns y ,f) grouped by country (column e1). However, I'm looking for the data to be split according to column e2. In other words, two tables of sum by country. One table for "con" and one table for "std" shown in column e2. Finally at the bottom of the two tables, I would like the overall sum /Totals for all the countries for the two columns (y,f). The lay outs for the two tables I'm looking for are also shown below in case my description isn't completely clear I would also like to be able to use the Totals of y and f for the two tables in other calculations. I can get the two sets of totals with the following commands but not the sums by country. colSums(test[test$e2=="std", c(3,4)]) colSums(test[test$e2=="con", c(3,4)]) I know there's an easy way to do this with a combination of colSums, by, aggregate but I can't seem to get it. std y f usa sum sum france sum sum can sum sum italy sum sum Totals sum sum con y f usa sum sum france sum sum can sum sum italy sum sum Totals sum sum e1 e2 y f 1 usa std 1 1 2 usa std 1 2 3 can con 1 3 4 france con 1 4 5 can std 1 5 6 italy con 1 6 7 usa std 2 7 8 usa std 2 8 9 can con 2 9 10 france con 2 10 11 can std 2 11 12 italy con 2 12 13 usa std 3 13 14 usa std 3 14 15 can con 3 15 16 france con 3 16 17 can std 3 17 18 italy con 3 18 19 usa std 4 19 20 usa std 4 20 21 can con 4 21 22 france con 4 22 23 can std 4 23 24 italy con 4 24 25 usa std 5 25 26 usa std 5 26 27 can con 5 27 28 france con 5 28 29 can std 5 29 30 italy con 5 30 31 usa std 6 31 32 usa std 6 32 33 can con 6 33 34 france con 6 34 35 can std 6 35 36 italy con 6 36 -- View this message in context: http://r.789695.n4.nabble.com/Not-sure-how-to-use-aggregate-colSums-by-tp3743258p3743258.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ 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.