Identify tied observations

Determines which elements of a vector are tied.

psi.tied(x)

Arguments

x	a numeric vector

Details

Unlike duplicated, this function returns all tied elements.

Value

a logical vector with the value TRUE at the positions of the tied elements.

See also

duplicated

Examples

v1 <- sample(1:6,12,replace=TRUE)
psi.tied(v1)
#>  [1] FALSE FALSE  TRUE  TRUE  TRUE  TRUE  TRUE  TRUE  TRUE  TRUE  TRUE  TRUE
duplicated(v1)
#>  [1] FALSE FALSE FALSE FALSE FALSE  TRUE  TRUE FALSE  TRUE  TRUE  TRUE  TRUE
d1 <- data.frame(v=v1, tied=psi.tied(v1), dup=duplicated(v1))
d1$flag <- ifelse(d1$tied==d1$dup, "", "different")
d1    # show the difference between `psi.tied' and `duplicated'
#>    v  tied   dup      flag
#> 1  6 FALSE FALSE          
#> 2  3 FALSE FALSE          
#> 3  2  TRUE FALSE different
#> 4  4  TRUE FALSE different
#> 5  1  TRUE FALSE different
#> 6  1  TRUE  TRUE          
#> 7  1  TRUE  TRUE          
#> 8  5  TRUE FALSE different
#> 9  2  TRUE  TRUE          
#> 10 5  TRUE  TRUE          
#> 11 2  TRUE  TRUE          
#> 12 4  TRUE  TRUE