Primes {DescTools} | R Documentation |
Find all prime numbers aka ‘primes’ less than n
.
Uses an obvious sieve method and some care, working with logical and integers to be quite fast.
Primes(n)
n |
a (typically positive integer) number. |
As the function only uses max(n)
, n
can also be a
vector of numbers.
numeric vector of all prime numbers \le n
.
This function was previously published in the package sfsmisc as primes
and has been integrated here without logical changes.
Bill Venables (\le n
); Martin Maechler gained another 40% speed,
working with logicals and integers.
(p1 <- Primes(100))
system.time(p1k <- Primes(1000)) # still lightning ..
stopifnot(length(p1k) == 168)