Why doesn't the UNIQUE function work with NaNs ?

Why doesn't the UNIQUE function work with NaNs ?

For example:

 >> unique([1 2 3 3 4 NaN NaN])

 ans =

      1     2     3     4   NaN   NaN

Answer 1

[MathWorks Support Team]

NaNs are special values in that two NaNs are not equal to each other. For example:

 >> NaN==NaN

 ans =

      0

This is why the NaNs in your vector are treated as different unique elements.

Also, you may wish to note that you can use the ISNAN function to check to data elements for NaNs.

A way to accomplish this functionality would use the attached function TSUNIQUE.