is.unsorted: Test if an Object is Not Sorted

Description Usage Arguments Value Note See Also


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


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



an R object with a class or a numeric, complex, character, logical or raw vector.


logical. Should missing values be removed before checking?


logical indicating if the check should be for strictly increasing values.


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().


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.

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