Hi [EMAIL PROTECTED] napsal dne 21.11.2007 10:45:55:
> Dear list, > > I'm still trying to calculate the sd for V2 for > each group in V1 if V3 is '0': > > > x > V1 V2 V3 > 1 A01 2.40 0 > 2 A01 3.40 1 > 3 A01 2.80 0 > 4 A02 3.20 0 > 5 A02 4.20 0 > 6 A03 2.98 1 > 7 A03 2.31 0 > 8 A04 4.20 0 > > # Work > x$vmean <- ave(x$V2, x$V1, x$V3 == 0, FUN = mean) > > # Work > x$vsd2 <- ave(x$V2, x$V1, FUN = sd) > > # Doesn't work > x$vsd <- ave(x$V2, x$V1, x$V3 == 0, FUN = sd) Problem comes from lapply(split(x$V2, interaction(x$V1, x$V3)), sd) specifically from > split(x$V2, interaction(x$V1, x$V3)) <snip> $A02.1 numeric(0) $A03.1 [1] 2.98 $A04.1 numeric(0) > sd(1) [1] NA > sd(numeric(0)) Error in var(x, na.rm = na.rm) : 'x' is empty I am not sure if what value shall sd, var or cov(x) return if x is empty. You probably have 2 options rewrite sd to handle empty vectors use another aggregate function together with some reordering, see eg. aggregate(x$V2, list(x$V1, x$V3 == 0), FUN = sd) Regards Petr > > Thank you for any help! > > Patrick > > ______________________________________________ > 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. ______________________________________________ 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.
