R: Test for uniquenes of records

is_unique {validate} | R Documentation

## Test for uniquenes of records

### Description

Test for uniqueness of columns or combinations of columns.

### Usage

    is_unique(...)

    all_unique(...)

    n_unique(...)

### Arguments

`...` | When used in a validation rule: a bare (unquoted) list of variable names. When used directly, a comma-separated list of vectors of equal length.

### Value

For `is_unique` A logical vector that is `FALSE` for each record that has a duplicate.

For `all_unique` a single `TRUE` or `FALSE`.

For `number_unique` a single number representing the number of unique values or value combinations in the arguments.

### See Also

Other cross-record-helpers: `contains_exactly()`, `do_by()`, `exists_any()`, `hb()`, `hierarchy()`, `is_complete()`, `is_linear_sequence()`

### Examples

    d <- data.frame(X = c('a','b','c','b'), Y = c('banana','apple','banana','apple'), Z=1:4)
    v <- validator(is_unique(X, Y))
    values(confront(d, v))

    # example with groupwise test
    df <- data.frame(x=c(rep("a",3), rep("b",3)),y=c(1,1,2,1:3))
    v <- validator(is_unique(y, by=x))
    values(confront(d,v))

[Package validate version 1.1.1 Index]