lapply and subsetting columns
lapply, r, subset, xts
Solution
`[` is a function
> args(xts:::`[.xts`)
function (x, i, j, drop = FALSE, which.i = FALSE, ...)
NULL
So, you can just use that. Either of these will do it.
lapply(x.m, '[', , c(1:4))
lapply(x.m, '[', j=c(1:4))
Problem
I would like the make the bit that uses `lapply()` more elegant...(i.e. a one liner would be good) rather than having to set up a function before. i.e. is there a standard function in which i can use `[,c(1:4)]` or something similar as an argument... so to make a reproducible example... ``` x <- xts(matrix(rnorm(500*8),ncol=8),Sys.Date()-500:1) x.m <- split(x,'months') ``` The following basically only takes the first 4 columns for each element of the list created from the split and thus i have to make a function that does this but i would like it to be more elegant somehow... ``` ff <- function(xts.obj){xts.obj[,c(1:4)]} g <- lapply(x.m, ff) ``` Thanks