Try this:

unlist(ifelse(q %in% names(x), x[q], NA))

On Tue, Jan 13, 2009 at 8:49 AM, Gundala Viswanath <gundalav@gmail.com>wrote:

> Dear all,
>
> Suppose I have a hash created with this
>
>  x <- list()
> for (i in c('test', 'some', 'more')){
>   x[[i]] <- runif(1)
> }
>
> then I want to extract the elem of that hash with
> a vector
>
> > q <- c("some", "more", "not_there")
>
> But why this failed?
>
> > extracted <- x[[q]]
> Error in x[[q]] : subscript out of bounds
>
> we expect the output of 'extracted' to be
> a vector as well. When the key is not present
> to give "NA" in vector
>
> - Gundala Viswanath
> Jakarta - Indonesia
>
> ______________________________________________
> 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.
>



-- 
Henrique Dallazuanna
Curitiba-Paraná-Brasil
25° 25' 40" S 49° 16' 22" O

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