Hi, R has a buildin function ?rowsum
rowsum(DF$Data,DF$Id,na.rm=T) ----- A R learner. -- View this message in context: http://r.789695.n4.nabble.com/Summing-by-index-tp2308332p2308411.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ R-help@r-project.org mailing list 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.
