z levels

[Vincent Le Fouest <vincent_lefouest@xxxxxxxxxx>]

Dear ferret users,

I have a ncdf file like, for example:

variable	k=1:5

---		1
---		2	
1.6		3
1.9		4
5		5

--- are missing values (I applied a mask).
My question would be: How to sort using ferret the number of z levels
(here 3) but without counting the levels where there are missing values?

Thanks in advance for your help,

Bye,

Vincent