match_dbl: A version of 'match' working exclusively on numeric data.
In DominikMueller64/dmisc: Dominik Mueller's R Code

Description Usage Arguments Value Author(s) See Also Examples

match_dbl returns a vector of the positions of (first) matches of its first argument in its second.

1 2	match_dbl(x, table, nomatch = NA_integer_, tolerance = sqrt(.Machine$double.eps))

`x`	A numeric vector with the values to be matched.
`table`	A numeric vector with the values to be matched against.
`nomatch`	An integer as the value to be returned in the case when no match is found.
`numeric`	scalar >= 0. Differences smaller than 'tolerance' are not recognized. The default value is close to 1.5e-8.

An integer vector giving the position in table of the first match if there is a match, otherwise nomatch.

Dominik Mueller

%in_dbl% for an numerical analog to %in%

# generate some random numeric data
set.seed(123)
table <- runif(1000L)
table <- sample(c(table, table)) # 'table' now contains duplicates
x <- sample(table, 100L)

m1 <- match(x, table)
m1_dbl <- match_dbl(x, table)
identical(m1, m1_dbl) # TRUE according to expectation

microbenchmark::microbenchmark(match(x, table),
                               match_dbl(x, table)) # speed is fine

# minimally disturb x
x <- x + runif(n = length(x), min = -1e-10, max = 1e-10)

identical(m1, match(x, table)) # now FALSE 
identical(m1_dbl, match_dbl(x, table)) # still TRUE
identical(m1_dbl, match_dbl(x, table, tolerance = 1e-11)) # also FALSE now