Extract Positions of Tied Elements — tiepos • bit64

tiepos returns the positions of those elements that participate in ties.

Usage

tiepos(x, ...)

# S3 method for class 'integer64'
tiepos(x, nties = NULL, method = NULL, ...)

Arguments

x: a vector or a data frame or an array or NULL.
...: ignored
nties: NULL or the number of tied values (including NA). Providing nties can speed-up when x has no cache. Note that a wrong nties can cause undefined behaviour up to a crash.
method: NULL for automatic method selection or a suitable low-level method, see details

Value

an integer vector of positions

Details

This function automatically chooses from several low-level functions considering the size of x and the availability of a cache.

Suitable methods are

sortordertie (fast ordering)
ordertie (memory saving ordering).

See also

rank.integer64() for possibly tied ranks and unipos.integer64() for positions of unique values.

Examples

x <- as.integer64(sample(c(rep(NA, 9), 1:9), 32, TRUE))
tiepos(x)
#>  [1]  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 16 17 18 19 20 21 22
#> [23] 23 24 25 26 27 28 29 30 31 32

stopifnot(identical(tiepos(x),  (1:length(x))[duplicated(x) | rev(duplicated(rev(x)))]))