Hi Andrew, Thank you very much! It works so well than I can expect.
All the best, Wei-Wei 2006/6/30, Andrew Robinson <[EMAIL PROTECTED]>: > Hi Wei-Wei, > > try this: > > eva.agg <- aggregate(x = list( > VC1=eva$VC1, > EO1=eva$EO1, > EO2=eva$EO2, > EO3=eva$EO3, > EO4=eva$EO4, > EO5=eva$EO5 > ), > by = list(PARTNO=eva$PARTNO), > FUN = mean, na.rm = TRUE) > > eva.agg$NUM <- aggregate(eva$PARTNO, list(eva$PARTNO), length) > > Cheers > > Andrew > ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
