How can I vectorize access to neighbour vector elements in R?

Question

I have the following vector

 v = c(F, F, F, T, F, F, F, F, F, T, F, F, F)

How can I change v so that the previous 2 elements and the following

Answer 1

Yet another approach. Create a set of lagged vectors, and or them together:

library(Hmisc)
library(functional)
within.distance <- function(x, d=2) {
  FLag <- function(x, shift) {
    x <- Lag(x, shift)
    x[is.na(x)] <- FALSE
    return(x)
  }

  l <- lapply((-d):d, Curry(FLag, x=x))
  return(Reduce(`|`, l))
}