Dear All, I would like to know, beside writing a function and then apply it to a list, or using a for loop, whether there is a one-line command to do the following. Suppose we have a list, each of whose components are numeric: > a <- vector("list",3) > a[[1]] <-c(1,2) > a[[2]] <-c(3,4) > a[[3]] <- c(5,6) > a [[1]] [1] 1 2
[[2]] [1] 3 4 [[3]] [1] 5 6 Target: I would like to extract from each of its components the first entry and store them into a vector, ie, to extract 1 from a[[1]], 3 from a[[2]], 5 from a[[3]], and store 1,3,5 into a vector without using for loops. Thank you, Chee [[alternative HTML version deleted]] ______________________________________________ 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.