Hi All, Suppose I have the following codes:
x = data.frame(A = rnorm(20), B = rnorm(20), C = rnorm(20)) a = list() a[["1.1"]] = x a[["1.2"]] = x b = list() b[["1.1"]] = c("A", "B") b[["1.2"]] = c("B", "C") Now I want to apply b to a like this, for each element of 'a', only select the corresponding columns listed in 'b'. For example, after that operation, a[["1,1"]] become subset(a[["1.1"]], select = c("A", "B")) a[["1,2"]] become subset(a[["1.1"]], select = c("B", "C")) Do you know how to do it without looping? Thanks. HXD [[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.