Hello, With a dataset that is about 1.4e6 rows long my.dat[seq(1:20),] date Cell_ID Classification WT_Depth Frac_ET_Satsfd 1999-04-08 974 3 3.585083 0.244561400 1999-04-08 1188 3 3.526001 0.123484700 1999-04-08 1189 3 3.187012 0.215916700 1999-04-08 1403 3 3.395020 0.163972900 1999-04-08 1409 3 2.368042 0.415165500 1999-04-08 1617 3 4.039917 0.003224544 1999-04-08 1618 3 3.457886 0.148585900 1999-04-08 1619 3 2.148926 0.475924300 1999-04-08 1620 2 1.523926 0.633190900 1999-04-08 1621 3 2.197998 0.469294300 1999-04-15 1622 7 2.759033 0.325698400 1999-04-15 1623 3 2.802002 0.313719600 1999-04-15 1624 3 3.062988 0.243275900 1999-04-15 1833 2 3.483032 0.141840700 1999-04-15 1834 2 3.128052 0.232235400 1999-04-15 1835 7 3.354004 0.176209000 1999-04-15 1836 3 2.691040 0.341234700 1999-04-15 1837 3 3.140991 0.228083800 1999-04-15 1838 3 2.392944 0.413379300 1999-04-15 2048 2 3.712036 0.084534560 . . . I use edm.func<-function(x){c(mu=mean(x),var=var(x))} output<-do.call("rbind",tapply(my.dat$Frac_ET_Satsfd,list(my.dat$date,my.dat$Classification),edm.func)) data.frame(output) mu var 1 0.7980007 0.03446669 2 0.7947966 0.03429280 3 0.8240736 0.02482441 . . 3573 0.4509044 0.03821251 3574 0.4484108 0.03856110 3575 0.4519150 0.03889944
There are 447 dates and 8 classifications (1-8). What is the best way to include the corresponding date and classification that goes with each row? Thanks Eric -- View this message in context: http://n4.nabble.com/formatting-do-call-output-tp1477702p1477702.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.