There are so many ways.... Here is one: aggregate(v ~ u, data=X, function(...) length(unique(...))) # u v # 1 T1 2 # 2 T2 1
Hope this helps Allan. On 22/07/10 12:52, Gildas Mazo wrote:
Dear R users, I want to aggregate data in the following way: ### X<- data.frame(u = c("T1","T1","T1","T2"), v=c("a","a","b","a")) X library(sqldf) sqlOut<- sqldf("select count(distinct(v)) from X group by u") sqlOut ### Now I want to get the same result without using SQL. How can I achieve that ? Thanks for your help, Gildas ______________________________________________ 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.