Thank you for suggestions, apparently data.table is much quicker than ddply and it's fantastic to use.
I forgot to mention in my topic I'm looking for alternative in R 2.10 version as on my platform our server runs older version of software which only support R up to version of R-2.10 (upgrade is currently impossible because of all applications that run on it) Ave function does not suffice as what I'm trying to do is: z1 <- past[, c(summary(lm(VAL~fy))$r.squared) , by = list(GEO_CNTRY_NAME,PROD_SEG_NAME)] z <- ddply(past, c("GEO_CNTRY_NAME","PROD_SEG_NAME"), function(x) summary(lm(VAL~fy,x))$r.squared) But when ave is not exactly doing what I need. Above code runs under a minute for my data set where as ave runs over 8 mins. Any ideas/help is greatly appreciated. -- View this message in context: http://r.789695.n4.nabble.com/ddply-from-plyr-package-any-alternatives-tp3765936p3767764.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.