for a simple example: x <- list() x[["a"]] <- list(a=c(1,2,3),b=c(3,4,5)) x[["b"]] <- list(a=c(6,7,8),b=c(9,10,11))
lapply(x,sum) this fails w/ Error in FUN(X[[1L]], ...) : invalid 'type' (list) of argument Just wondering if I have overlooked something obvious. one can also do: lapply(x,lapply,sum) but that assumes that you already know how many levels you have, and that all the levels are consistent. -Whit ______________________________________________ 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.