[R] list of list

[peter dalgaard]

On 16 Feb 2015, at 17:43 , Troels Ring <tring at gvdnet.dk> wrote:

> Dear friends - this is simple I know but I can figure it out without your help.
> I have for each of 2195 instances 10 variables measured at specific times from 6 to several hundred, so if I just take one of the instances, I can make a list of the 10 variables together with their variable times. But when I have 2195 such instances I cannot get it how to make a list of these individual lists
> 
> As a toy example demonstrating mercilessly my problem, if ASL[j] is mean to take the list of here 5 entries made in RES[[i]] and I write this (ignoring the times) it certainly doesn't work
> ASL <- list()
> RES <- list()
> for (j in 1:5){
> for (i in 1:5)
> ASL[[j]] <-
> RES[[i]] <- i^j }

Your description doesn't quite make sense to me, but if you really want ASL to be a list of lists, you want each member to be a list and the (i,j)th item accessed as ASL[[i]][[j]]. So I'd expect to see something like

for (j .... {
	ASL[[j]] <- list()
	for (i ....
		ASL[[j]][[|]] <- ....
}

You also really don't want to start with an empty list and extend it on every iteration. If you need an n-element list, preallocate it using vector(n, mode="list").

If the above doesn't make sense, rephrase the question....


-- 
Peter Dalgaard, Professor,
Center for Statistics, Copenhagen Business School
Solbjerg Plads 3, 2000 Frederiksberg, Denmark
Phone: (+45)38153501
Email: pd.mes at cbs.dk  Priv: PDalgd at gmail.com