R: loop through data frame extracting subset of data depending on date

Question

I have a large data frame that consists of data that looks something like this:

        date    w    x    y    z    region
1    2012 01    21   43   12    3   NO         


        

Answer 1

You can split your data.frame into a list of data.frames like this:

list.of.dfs<-by(data,data$date)