R: Extract Positions of Tied Elements

tiepos {bit64} | R Documentation

## Extract Positions of Tied Elements

### Description

`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`.
`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
`...` | ignored

### 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) and `ordertie` (memory saving ordering).

### Value

an integer vector of positions

### Author(s)

Jens Oehlschlägel <Jens.Oehlschlaegel@truecluster.com>

### 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)

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

[Package bit64 version 0.9-7 Index]