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Interleave many vectors into one vector

Source: R/slice-interleave.R
vec_interleave.Rd

vec_interleave() combines multiple vectors together, much like vec_c(), but does so in such a way that the elements of each vector are interleaved together.

It is a more efficient equivalent to the following usage of vec_c():

vec_interleave(x, y) == vec_c(x[1], y[1], x[2], y[2], ..., x[n], y[n])

Usage

vec_interleave(
  ...,
  .size = NULL,
  .ptype = NULL,
  .name_spec = NULL,
  .name_repair = c("minimal", "unique", "check_unique", "universal", "unique_quiet",
    "universal_quiet"),
  .error_call = current_env()
)

Arguments

...

Vectors to interleave.

.size

The expected size of each vector. If not provided, computed automatically by vec_size_common(). Each vector will be recycled to this size.

.ptype

The expected type of each vector. If not provided, computed automatically by vec_ptype_common(). Each vector will be cast to this type.

.name_spec

A name specification for combining inner and outer names. This is relevant for inputs passed with a name, when these inputs are themselves named, like outer = c(inner = 1), or when they have length greater than 1: outer = 1:2. By default, these cases trigger an error. You can resolve the error by providing a specification that describes how to combine the names or the indices of the inner vector with the name of the input. This specification can be:

  • A function of two arguments. The outer name is passed as a string to the first argument, and the inner names or positions are passed as second argument.

  • An anonymous function as a purrr-style formula.

  • A glue specification of the form "{outer}_{inner}".

  • "inner", in which case outer names are ignored, and inner names are used if they exist. Note that outer names may still be used to provide informative error messages.

  • An rlang::zap() object, in which case both outer and inner names are ignored and the result is unnamed.

See the name specification topic.

.name_repair

How to repair names, see repair options in vec_as_names().

.error_call

The execution environment of a currently running function, e.g. caller_env(). The function will be mentioned in error messages as the source of the error. See the call argument of abort() for more information.

Dependencies

vctrs dependencies

Examples

# The most common case is to interleave two vectors
vec_interleave(1:3, 4:6)
#> [1] 1 4 2 5 3 6

# But you aren't restricted to just two
vec_interleave(1:3, 4:6, 7:9, 10:12)
#>  [1]  1  4  7 10  2  5  8 11  3  6  9 12

# You can also interleave data frames
x <- data_frame(x = 1:2, y = c("a", "b"))
y <- data_frame(x = 3:4, y = c("c", "d"))

vec_interleave(x, y)
#> # A tibble: 4 × 2
#>       x y    
#>   <int> <chr>
#> 1     1 a    
#> 2     3 c    
#> 3     2 b    
#> 4     4 d    

# `.size` can be used to recycle size 1 elements before interleaving
vec_interleave(1, 2, .size = 3)
#> [1] 1 2 1 2 1 2

# `.ptype` can be used to enforce a particular type
typeof(vec_interleave(1, 2, .ptype = integer()))
#> [1] "integer"