vec_match {vctrs} | R Documentation |
vec_in()
returns a logical vector based on whether needle
is found in
haystack. vec_match()
returns an integer vector giving location of
needle
in haystack
, or NA
if it's not found.
vec_match(needles, haystack) vec_in(needles, haystack)
needles, haystack |
Vector of
|
vec_in()
is equivalent to %in%; vec_match()
is equivalen to match()
.
A vector the same length as needles
. vec_in()
returns a
logical vector; vec_match()
returns an integer vector.
In most cases, missing values are not considered to be equal, i.e.
NA == NA
is not TRUE
. This behaviour would be unappealing here,
so these functions consider all NAs
to be equal. (Similarly,
all NaN
are also considered to be equal.)
hadley <- strsplit("hadley", "")[[1]] vec_match(hadley, letters) vowels <- c("a", "e", "i", "o", "u") vec_match(hadley, vowels) vec_in(hadley, vowels) # Only the first index of duplicates is returned vec_match(c("a", "b"), c("a", "b", "a", "b"))