[R] Extract elements from objects in a list

[Jeremy Miles]

Hi All,

I want to extract elements of elements in a list.

Here's an example of what I mean:

If I create a list:

x <- as.list(100)
for(loop in c(1:100)) {
	x[[loop]] <- summary(runif(100))
	}


> head(x)
[[1]]
   Min. 1st Qu.  Median    Mean 3rd Qu.    Max.
0.02271 0.25260 0.58130 0.52120 0.77270 0.99670

[[2]]
    Min.  1st Qu.   Median     Mean  3rd Qu.     Max.
0.006796 0.259700 0.528100 0.515500 0.781900 0.993100

[[3]]
   Min. 1st Qu.  Median    Mean 3rd Qu.    Max.
0.00927 0.22800 0.40780 0.46410 0.69460 0.98780

I want to extract (say) the medians as a vector.  This would be:
x[[1]][[3]]
x[[2]][[3]]
x[[3]][[3]]

I thought there would be a way of doing this with something like
apply(), but I cannot work it out.  Is there a way of doing this
without a loop?  Thanks,

Jeremy