Split a vector into a list of vectors

Splits x into a list of consecutive groups. You MUST specify exactly one of size_of_each_group or number_of_groups. Neither argument, or both arguments, is an error.

Usage

easy_split(x, size_of_each_group = NULL, number_of_groups = NULL)

Arguments

x

The vector to split.

size_of_each_group

The number of elements in each group. The last group may hold fewer.

number_of_groups

The number of groups you request. The function can return fewer groups than you request. See Details.

Value

A list of vectors, holding the elements of x in their original order. Every element has the same length except the last, which may be shorter.

Details

Every group has the same length except the last, which may be shorter. The function preserves the original order of x. It names the list elements "1", "2" and so on.

number_of_groups is a request, not a guarantee. The function computes the group size as ceiling(length(x) / number_of_groups). The number of groups it returns is then ceiling(length(x) / ceiling(length(x) / number_of_groups)). That count can be smaller than number_of_groups. For example, easy_split(1:4, number_of_groups = 3) returns two groups of two.

See also

vignette("csutil", package = "csutil"), which splits letters[1:20] both ways.

Examples

easy_split(letters[1:20], size_of_each_group = 3)
#> $`1`
#> [1] "a" "b" "c"
#> 
#> $`2`
#> [1] "d" "e" "f"
#> 
#> $`3`
#> [1] "g" "h" "i"
#> 
#> $`4`
#> [1] "j" "k" "l"
#> 
#> $`5`
#> [1] "m" "n" "o"
#> 
#> $`6`
#> [1] "p" "q" "r"
#> 
#> $`7`
#> [1] "s" "t"
#> 
easy_split(letters[1:20], number_of_groups = 3)
#> $`1`
#> [1] "a" "b" "c" "d" "e" "f" "g"
#> 
#> $`2`
#> [1] "h" "i" "j" "k" "l" "m" "n"
#> 
#> $`3`
#> [1] "o" "p" "q" "r" "s" "t"
#> 

# number_of_groups is a request: this asks for 3 groups and returns 2
easy_split(1:4, number_of_groups = 3)
#> $`1`
#> [1] 1 2
#> 
#> $`2`
#> [1] 3 4
#>