Hi, Better would be to show a reproducible example using ?dput() and the codes you used. Assuming that you tried something like this: lst1<- list(1:10,c(5,4,3),4:15) mean(lst1) #[1] NA #Warning message: #In mean.default(lst1) : argument is not numeric or logical: returning NA sapply(lst1,mean) #also depends upon the list elements. In the example I used, it is a vector. #[1] 5.5 4.0 9.5
#or lapply(lst1,mean) #[[1]] #[1] 5.5 # #[[2]] #[1] 4 # #[[3]] #[1] 9.5 #Suppose, your list elements are: set.seed(24) lst2<- list(as.data.frame(matrix(sample(1:10,5*4,replace=TRUE),ncol=5)),as.data.frame(matrix(sample(1:40,8*5,replace=TRUE),ncol=8))) #and you wanted to find the column means lapply(lst2,colMeans) #[[1]] # V1 V2 V3 V4 V5 #5.00 7.00 5.75 7.00 2.75 # #[[2]] # V1 V2 V3 V4 V5 V6 V7 V8 #14.4 16.8 16.4 26.4 11.4 12.0 24.8 16.8 Hope it helps. A.K. When I try to apply mean to a list, I get the answer : argument is not numeric or logical: returning NA Could you help me? (I am a very beginner) ______________________________________________ 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.
