Vector of Vectors
This may help in understanding how to access the list: notice that I am using numeric indices and using the '[[' operator
# generate a list with a varying number of values myList <- list() # initialize for (i in 1:10) myList[[i]] <- seq(i) myList
[[1]] [1] 1 [[2]] [1] 1 2 [[3]] [1] 1 2 3 [[4]] [1] 1 2 3 4 [[5]] [1] 1 2 3 4 5 [[6]] [1] 1 2 3 4 5 6 [[7]] [1] 1 2 3 4 5 6 7 [[8]] [1] 1 2 3 4 5 6 7 8 [[9]] [1] 1 2 3 4 5 6 7 8 9 [[10]] [1] 1 2 3 4 5 6 7 8 9 10
myList[[4]] # 1,2,3,4
[1] 1 2 3 4
myList[[4]][2:3] # 2, 3
[1] 2 3
On Wed, Apr 1, 2009 at 12:58 PM, Shawn Garbett
<Shawn.P.Garbett at vanderbilt.edu> wrote:
I have a matrix of data. I need to scan the matrix and find every sequence from maxima to maxima across a row. I can write a loop to do this easily. Problem is, I can't figure out how to store the results. Each result is a vector of widely varying lengths. Ideally I'd like a vector of these, i.e. a vector of vectors, so I can quickly iterate through them and compute correlation coefficients. Here's a transcript of my fuddling to date:
x <- c(1,2,3)
y <- c(4,5)
v <- list("1"=x, "2"=y)
unlist(v["1"])
11 12 13 ?1 ?2 ?3
unlist(v["1"])[1]
11 ?1
unlist(v["1"])[2]
12 ?2
unlist(v["1"])[3]
13 ?3
unlist(v["2"])[3]
<NA> ?NA
unlist(v["2"])[2]
22 ?5
v <- c(x,y) v
[1] 1 2 3 4 5
v <- vector() v <- merge(v, x) v
? ? [,1] [,2] attr(,"row.names") integer(0)
v[1]
[1] NA
As you can see, vectors aren't very cooperative and lists are downright baffling to me. Shawn Garbett <shawn.p.garbett at vanderbilt.edu> Vanderbilt Cancer Biology 220 Pierce Ave, PRB 715AA Nashville, TN 37232 Office: 615.936.1975 Cell: 615.397.8737
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Jim Holtman Cincinnati, OH +1 513 646 9390 What is the problem that you are trying to solve?