Bucket a numeric vector into n groups

ntile() is a sort of very rough rank, which breaks the input vector into n buckets. If length(x) is not an integer multiple of n, the size of the buckets will differ by up to one, with larger buckets coming first.

Unlike other ranking functions, ntile() ignores ties: it will create evenly sized buckets even if the same value of x ends up in different buckets.

Usage

ntile(x = row_number(), n)

Arguments

x

A vector to rank

By default, the smallest values will get the smallest ranks. Use desc() to reverse the direction so the largest values get the smallest ranks.

Missing values will be given rank NA. Use coalesce(x, Inf) or coalesce(x, -Inf) if you want to treat them as the largest or smallest values respectively.

To rank by multiple columns at once, supply a data frame.

n

Number of groups to bucket into

See also

Other ranking functions: percent_rank(), row_number()

Examples

x <- c(5, 1, 3, 2, 2, NA)
ntile(x, 2)
#> [1]  2  1  2  1  1 NA
ntile(x, 4)
#> [1]  4  1  3  1  2 NA

# If the bucket sizes are uneven, the larger buckets come first
ntile(1:8, 3)
#> [1] 1 1 1 2 2 2 3 3

# Ties are ignored
ntile(rep(1, 8), 3)
#> [1] 1 1 1 2 2 2 3 3