Re: [R] Using PLYR to apply a custom function to a data frame

Thanks everyone. The mutate function worked great: all2<- mutate(all1,upper=p75+1.5*(p75-p25),lower=p25-1.5*(p75-p25)) -- View this message in context: http://r.789695.n4.nabble.com/Using-PLYR-to-apply-a-custom-function-to-a-data-frame-tp4663897p4663902.html Sent from the R help mailing list

Re: [R] Using PLYR to apply a custom function to a data frame

Hi, You could try ?within() set.seed(25) ALL<- data.frame(q3=sample(15:30,10,replace=TRUE), q1=sample(1:14,10,replace=TRUE)) res<-within(ALL,{lower<-q1- 1.5*(q3-q1);upper<-q3+1.5*(q3-q1)})  res #   q3 q1 upper lower #1  21  5  45.0 -19.0 #2  26  6  56.0 -24.0 #3  17 14  21.5   9.5 #4  29  9  59.