Split a vector into a list of vectors

Splits x into a list of consecutive groups. Specify exactly one of size_of_each_group or number_of_groups; supplying neither, or supplying both, is an error.

Usage

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

Arguments

x

The vector to be 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 requested. Fewer groups than requested can be returned; 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 original order of x is preserved, and the list elements are named "1", "2" and so on.

number_of_groups is a request, not a guarantee. The group size is computed as ceiling(length(x) / number_of_groups), so the number of groups actually returned is ceiling(length(x) / ceiling(length(x) / number_of_groups)), which 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
#>