How Do I create a Column formula for N Categories?

[#1]

I would like to create a column formula that provides a count of the number of distinct values in a column.  I can use the Column viewer, Show summary function in JMP 15 but I want to have that value in a column for use in other calculations.

For example in the Big Class Table - N Items in column "Sex" should show 2 as 2 distinct values.

[#2]

here is a wish to add such a functionality
... to JSL
... to New Column Formula
... to Graph Builder

Col N Categories 

I guess there are only a few JMP users in the world who don't need it ; )
Most JMP users will be excited to see such a functionality in a future version of JMP (... along with dense ranking )

[#3]

[removed] didn't show up at the right position.