[R] Extracting the first element of a list

[Uwe Ligges]

Ross Darnell wrote:
> 
> Perhaps some kind person might show me the way to extract the first element of a list.
> 
> The example is
> 
> tmp <- c("A", "B C","BC D")
> 
> I want the first "word" from each of these elements, i.e. "A" ,"B" ,"BC"
> 
> strsplit(tmp," ") returns
> 
> [[1]]
> [1] "A"
> 
> [[2]]
> [1] "B" "C"
> 
> [[3]]
> [1] "BC" "D"
> 
> I have had no success in trying to extract the first element.
> 
> Of course there may be another way to get the same result.

For the first element of a list L: 
 L[[1]]
For the first elements of all elements (vector) of the list:
 lapply(L, function(x) x[1])

Uwe Ligges
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