Great. Thanks, Jim. _____
From: jim holtman [mailto:[EMAIL PROTECTED] Sent: Sunday, December 24, 2006 1:11 AM To: [EMAIL PROTECTED] Cc: [EMAIL PROTECTED] Subject: Re: [R] how to 'get' an object that is part of a list use 'eval' and 'parse' > xx $a [1] 1 2 3 4 5 $b [1] "a" "b" "c" "d" "e" > eval(parse(text='xx$a')) [1] 1 2 3 4 5 > So that way you can pass in the character string and then 'parse' it. On 12/24/06, Christos Hatzis <[EMAIL PROTECTED]> wrote: This might be an trivial thing but I am stuck. Consider: xx <- list(a=1:5, b=letters[1:5]) Although object xx is accessible through its name, how can object xx$b be accessed similarly through its name? > get("xx") $a [1] 1 2 3 4 5 $b [1] "a" "b" "c" "d" "e" > get("xx$b") Error in get(x, envir, mode, inherits) : variable "xx$b" was not found get("xx")$b will not work in my case because it will probably require parsing to make it work within a function. E.g. my.length <- function(...) { names <- as.character(substitute(list(...)))[-1] sapply(names, FUN=function(x){y <- get(x); length(y)}) } > my.length(xx) xx 2 > my.length (xx$a) Error in get(x, envir, mode, inherits) : variable "xx$a" was not found > my.length(xx$a, xx$b) Error in get(x, envir, mode, inherits) : variable "xx$a" was not found Thank you. Christos Hatzis, Ph.D. Nuvera Biosciences, Inc. 400 West Cummings Park Suite 5350 Woburn, MA 01801 Tel: 781-938-3830 www.nuverabio.com ______________________________________________ [email protected] 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. -- Jim Holtman Cincinnati, OH +1 513 646 9390 What is the problem you are trying to solve? [[alternative HTML version deleted]] ______________________________________________ [email protected] 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.
