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library(iterators)
# return an iterator that returns subvectors of a sequence
# of a specified length.
# can specify either "chunks" or "chunkSize" arguments
# since that is what the "idiv" function supports.
iseq <- function(n, ...) {
i <- 1
it <- idiv(n, ...)
nextEl <- function() {
n <- nextElem(it)
x <- seq(i, length=n)
i <<- i + n
x
}
obj <- list(nextElem=nextEl)
class(obj) <- c('iseq', 'abstractiter', 'iter')
obj
}
# create a sequence iterator that returns three subvectors
it <- iseq(25, chunks=3)
print(as.list(it))
# create a sequence iterator that returns subvectors
# with a maximum length of 10
it <- iseq(25, chunkSize=10)
print(as.list(it))
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