[R] with lapply() how can you retrieve the name of the object

[jim holtman]

forgot one step:

> z <- lapply(names(test.list), function(x){
+     cbind(test.list[[x]], var.2=x)
+ })
> names(z) <- names(test.list)
> z
$a
  var.1 var.2
1     1     a
2     2     a
3     3     a
4     4     a
5     5     a

$b
  var.1 var.2
1    11     b
2    12     b
3    13     b
4    14     b
5    15     b

>


On Fri, Jul 18, 2008 at 6:21 PM, Andrew Yee <yee at post.harvard.edu> wrote:
> In the following code, I'd like to be able to create a new variable
> containing the value of the names of the list.
>
>
> a <- data.frame(var.1 = 1:5)
> b <- data.frame(var.1 = 11:15)
>
> test.list <- list(a=a, b=b)
>
> # in this case, names(test.list) is "a" and "b"
>
> # and I'd like to use lapply() so that
> # I get something that looks like
> # var.1 var.2
> #     1  a
> #     2  a
> #     3  a
> #etc.
>
> new.list <- lapply(test.list, function(x) {x$var.2 <- names(x)
>                                            x} )
>
>
> # the above clearly doesn't do it.  How do you pull out the names of the
> thing that is being lapplied?
>
> Thanks,
> Andrew
>
>        [[alternative HTML version deleted]]
>
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>



-- 
Jim Holtman
Cincinnati, OH
+1 513 646 9390

What is the problem you are trying to solve?