Hi all, I want to calculate the difference between successive row values to the first row value within year. How do I get that?
Here is the sample of data Year Num 2001 25 2001 75 2001 150 2002 30 2002 85 2002 95 Desired output Year Num diff 2001 25 0 2001 75 50 2001 150 125 2002 30 0 2002 85 55 2002 95 65 Thank you. ______________________________________________ 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.
