Arun, This worked perfectly - Thank you. The dates are actually full Chron dates so it was easy to sort first by date. I ended up using your Method 2 for speed.
I was wondering - if you don't mind - you could briefly explain some of the syntax. I have seen .I and .SD but am not familiar quite with what they mean. I'm assuming .N is last? Is there a syntax for the first (.n?) or the 5th (.5?) Is '.I' saying find the index that meets this criterion? And .SD find the group that meet the criterion? Thank you, Ben -- View this message in context: http://r.789695.n4.nabble.com/Subsetting-By-Row-Function-tp4694221p4694227.html Sent from the datatable-help mailing list archive at Nabble.com. _______________________________________________ datatable-help mailing list [email protected] https://lists.r-forge.r-project.org/cgi-bin/mailman/listinfo/datatable-help
