Uniqueness of the array elements

[MimiKLM]

Hi,

I've got the 1D array of the DBL values.

How to quickly check all of they are unique?

[RavensFan]

Index through the array in a loop.  Search that 1-D array for each element.  If the item is unique, there should be exactly 1 of that element in there.

[Darin.K]

Sort. Then check each against its predecessor. Careful with equality checks, you may want to allow a small range to be considered equal.

[thoult]

What happens if you're comparing two NaN entries in a numeric array?

Edit - by which I mean to say that, as usual, altenbach has a pretty good example of this - have a read through the comments here