R: Test if an Object is Not Sorted

is.unsorted {base} | R Documentation

## Test if an Object is Not Sorted

### Description

Test if an object is not sorted (in increasing order), without the cost of sorting it.

### Usage

    is.unsorted(x, na.rm = FALSE, strictly = FALSE)

### Arguments

`x` | an R object with a class or a numeric, complex, character, logical or raw vector.
`na.rm` | logical. Should missing values be removed before checking?
`strictly` | logical indicating if the check should be for strictly increasing values.

### Details

`is.unsorted` is generic: you can write methods to handle specific classes of objects, see InternalMethods.

### Value

A length-one logical value. All objects of length 0 or 1 are sorted. Otherwise, the result will be `NA` except for atomic vectors and objects with an S3 class (where the `>=` or `>` method is used to compare `x[i]` with `x[i-1]` for `i` in `2:length(x)`) or with an S4 class where you have to provide a method for `is.unsorted()`.

### Note

This function is designed for objects with one-dimensional indices, as described above. Data frames, matrices and other arrays may give surprising results.

### See Also

`sort`, `order`.

[Package base version 4.0.5 Index]