subsetting a list of matrices
On Tue, 2006-02-28 at 17:14 +0000, Federico Calboli wrote:
Hi All, I have a list of matrices:
x
[,1] [,2] [1,] 1 4 [2,] 2 5 [3,] 3 6
y
[,1] [,2] [,3] [,4] [,5] [,6] [1,] 18 21 24 27 30 33 [2,] 19 22 25 28 31 34 [3,] 20 23 26 29 32 35
z =list(x,y)
I want to create a second list that is has a subset each matrix in the list subsetting so I get the 2nd and 3rd row of each (and all columns). How could I do that (apart from looping)? Regards, Federico Calboli
Here is one approach:
lapply(z, function(x) x[2:3, ])
[[1]]
[,1] [,2]
[1,] 2 5
[2,] 3 6
[[2]]
[,1] [,2] [,3] [,4] [,5] [,6]
[1,] 19 22 25 28 31 34
[2,] 20 23 26 29 32 35
HTH,
Marc Schwartz