Zip an object with itself after inserting a variable number of steps. For
instance, with a step of 1, a b c would become a,b, b,c, c,NA.
Arguments
- x
Object with a vector structure.
- step
Remove the first step entries from the object before zipping
it with itself.
Value
A S4Vectors::Pairs object with a copy of x in the first slot,
and x with step elements removed from its head and complemented with
NAs in the second slot.
Details
This is a programming pattern that I use a lot in this package, to prepare
vectors fro parallel processing. I typically use it on metadata columns
of GBreaks objects. I created this function because I always forget if I
should use head or tail, which causes bugs or delays in development.
Examples
zipWithNext(LETTERS, step = 2)
#> Pairs object with 26 pairs and 0 metadata columns:
#> first second
#> <character> <character>
#> [1] A C
#> [2] B D
#> [3] C E
#> [4] D F
#> [5] E G
#> ... ... ...
#> [22] V X
#> [23] W Y
#> [24] X Z
#> [25] Y <NA>
#> [26] Z <NA>