Hi All— I have a data frame with over 13000 rows and 4 columns. A mini data frame is given at the bottom. I want to split the data frame into lists each corresponds to single year which ranges from 1990 to 2018). I wanted to use the split function, but it requires a vector of the same length as MyDate which contains many multiples of each year. Any help is highly appreciated.
I want the following results: List 1990 MyDate MyNo MyDes 1990 1990 1990 …... List 2000 2000 2000 2000 …... List 2001 2001 2001 2001 2001 …... List 2018 2018 2018 2018 …... Sample data frame mydf <- data.frame(MyDate=c("1990-01-01","1990-04-07","2000-04-05","2018-01-04"),MyNo=c(1,2,3,4),MyDes=c("AA","BB","CC","DD")) EK ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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.