R help - Jun 2006 - apply a function to several lists' components

Dear R-user
I have 100 lists.
Each list has several components.
For example,
>data1
$a
[1] 1 2

$b
[1] 3 4

$c
[1] 5

There are data1, data2,...., data100. All lists have the same number and the 
same name of components.


Is there any function I can use for applying to only a specific component 
across 100 lists?
(e.g.,  taking mean of $c acorss 100 lists) or do I need to write my own 
function for that?

Thank you.

Taka,

Maybe this helps

( data1 = list(a=c(1,2), b=c(3,4), c=c(5,6,7)) )
( data2 = list(a=c(10,11), b=c(30,40), c=c(70,80)) )

cc <- NULL
for(data in ls(pattern="^data[0-9]+$")) {
  cc <- c(cc, with(get(data), c))
}

mean(cc)

JeeBee.


On Fri, 30 Jun 2006 09:50:51 -0500, Taka Matzmoto wrote:
> Dear R-user
> I have 100 lists.
> Each list has several components.
> For example,
> 
>>data1
> $a
> [1] 1 2
> 
> $b
> [1] 3 4
> 
> $c
> [1] 5
> 
> There are data1, data2,...., data100. All lists have the same number and
the
> same name of components.
> 
> 
> Is there any function I can use for applying to only a specific component 
> across 100 lists?
> (e.g.,  taking mean of $c acorss 100 lists) or do I need to write my own 
> function for that?
> 
> Thank you.
> 
> Taka,
> 
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