Sorry, that second example should be

alist <- lapply(seq(along = alist), function(i) {
                alist[[i]]$name <- new.names[i])
                alist
         })

-roger

Roger D. Peng wrote:
For the first case, I actually do this pretty often and usually use something like:

as.vector(sapply(alist, "[[", "vec"))

For the second case, I think you just need to use lapply():

alist <- lapply(seq(along = alist), function(i)
        alist[[i]]$name <- new.names[i])

-roger

Waichler, Scott R wrote:

For a long time I've wanted a way to conveniently extract multiple elements
from a list, which [[ doesn't allow. Can anyone suggest an efficient
function to do this? Wouldn't it be a sensible addition to R?


For example,

alist <- list()
alist[[1]] <- list()
alist[[1]]$name <- "first"
alist[[1]]$vec <- 1:4
alist[[2]] <- list()
alist[[2]]$name <- "second"
alist[[2]]$vec <- 5:8
both.vec <- c(alist[[1]]$vec, alist[[2]]$vec)

Can I get both.vec without c() or an explicit loop?

and

new.names <- c("one", "two")
alist[[1]]$name <- new.names[1]
alist[[2]]$name <- new.names[2]

Could I assign the new values in a quasi-vectorized way?

Thanks,
Scott Waichler
Pacific Northwest National Laboratory
Richland, WA   USA

______________________________________________
[EMAIL PROTECTED] mailing list
https://www.stat.math.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html



______________________________________________
[EMAIL PROTECTED] mailing list
https://www.stat.math.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html



______________________________________________ [EMAIL PROTECTED] mailing list https://www.stat.math.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html

Reply via email to