according to the documentation of the cast function in the reshape function, I would expect this bit of code from the examples to calculate marginal means over only the 'diet' variable.
#Chick weight example names(ChickWeight) <- tolower(names(ChickWeight)) chick_m <- melt(ChickWeight, id=2:4, na.rm=TRUE) cast(chick_m, diet + chick ~ time, mean, margins="diet") But, summary(cast(subset(chick_m, time == 0), diet + chick ~ time, mean, margins="diet")) returns: diet chick 0 1 :21 (all) : 4 Min. :39.00 2 :11 18 : 1 1st Qu.:40.85 3 :11 16 : 1 Median :41.00 4 :11 15 : 1 Mean :41.05 (all): 0 13 : 1 3rd Qu.:42.00 9 : 1 Max. :43.00 (Other):45 which shows that it calculated margins on the 'chick' column as well. this behavior causes great problems for me when in my data one of the columns is a non-factor column, eg a Date, but the unrequested margining behavior turns that column into a factor. am I missing something? Thanks, Mike -- View this message in context: http://www.nabble.com/bug-in-%27margins%27-behavior-in-reshape---cast-tp18737649p18737649.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.