Question

I have a somewhat dumb R question. If I have a matrix (or dataframe, whichever is easier to work with) like:

Year  Match
2008   1808
2008 137088
2008      1
2008  56846
2007   2704
2007 169876
2007  75750
2006   2639
2006 193990
2006      2

And I wanted to sum each of the match counts for the years (so, e.g. the 2008 row would be 2008 195743, how would I go about doing this? I’ve got a few solutions in my head but they are all needlessly complicated and R tends to have some much easier solution tucked away somewhere.

You can generate the same matrix above with:

structure(c(2008L, 2008L, 2008L, 2008L, 2007L, 2007L, 2007L, 
2006L, 2006L, 2006L, 1808L, 137088L, 1L, 56846L, 2704L, 169876L, 
75750L, 2639L, 193990L, 2L), .Dim = c(10L, 2L), .Dimnames = list(
NULL, c("Year", "Match")))

Thanks for any help you can offer.

Answer 1

aggregate(x = df$Match, by = list(df$Year), FUN = sum), assuming df is your data frame above.