R help - Oct 2010 - lapply to subsets

Dear R,

I have a silly question concerns with *apply. Say I have a list called A,

A <- list(a  =  array(1:20, c(2, 2, 5)), b  = array(1:30, c(2, 3, 5)))

I wish to calculate the mean of A$a, and A$b w.r.t. their third dimension so
I did

lapply(A,apply,c(1,2),mean)

Now if I still wish to do the above task but take away some burn-in, e.g. do
not take A$a[,,1:2],and A$b[,,1:2] into account. How can I do then?


Thanks!



Feng


-- 
Feng Li
Department of Statistics
Stockholm University
106 91 Stockholm, Sweden
http://feng.li/

	[[alternative HTML version deleted]]

Hello Feng,

I think you just want this...

lapply(A, function(x) apply(x[,,-c(1,2)], c(1,2), mean))

Michael


On 13 October 2010 04:00, Feng Li <feng.li at stat.su.se>
wrote:
> Dear R,
>
> I have a silly question concerns with *apply. Say I have a list called A,
>
> A <- list(a ?= ?array(1:20, c(2, 2, 5)), b ?= array(1:30, c(2, 3, 5)))
>
> I wish to calculate the mean of A$a, and A$b w.r.t. their third dimension
so
> I did
>
> lapply(A,apply,c(1,2),mean)
>
> Now if I still wish to do the above task but take away some burn-in, e.g.
do
> not take A$a[,,1:2],and A$b[,,1:2] into account. How can I do then?
>
>
> Thanks!
>
>
>
> Feng
>
>
> --
> Feng Li
> Department of Statistics
> Stockholm University
> 106 91 Stockholm, Sweden
> http://feng.li/
>
> ? ? ? ?[[alternative HTML version deleted]]
>
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