help with for loop
diff.zoo in the zoo package can take a vector of lags: library(zoo) z <- zoo(seq(10)^2) diff(z, 1:4) There are three vignettes (pdf documents) that come with zoo that have more info on the package. On Fri, Jan 1, 2010 at 8:16 PM, Rafael Moral
<rafa_moral2004 at yahoo.com.br> wrote:
Dear useRs,
I want to write a function that generates all the possible combinations of diff().
Example:
If my vector has length 5, I need the diff() until lag=4 ->
c(diff(my.vec), diff(my.vec, lag=2), diff(my.vec, lag=3), diff(my.vec, lag=4))
If it has length 4, I need until lag=3 ->
c(diff(my.vec), diff(my.vec, lag=2), diff(my.vec, lag=3))
So, it must be until lag=(length(my.vec)-1).
The function I've written is:
dif <- function(my.vec) {
for(i in 2:(length(my.vec)-1)) {
x.dif <- c(diff(my.vec), diff(my.vec, lag=i))
}
return(x.dif)
}
But it only returns the first diff() (lag=1) and the last one ( diff(my.vec, lag=(length(my.vec)-1)?? )
Example:
my.vec = c(1,2,3,2) dif(my.vec)
[1]? 1? 1 -1? 1 What I wanted to get was:
c(diff(my.vec), diff(my.vec, lag=2), diff(my.vec, lag=3))
[1]? 1? 1 -1? 2? 0? 1 Is there a way of computing it so R understands what I want? Thanks in advance, happy new year for everyone! Kind regards, Rafael. ? ? ?____________________________________________________________________________________ [[elided Yahoo spam]] ? ? ? ?[[alternative HTML version deleted]]
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