Re: How do I mask out to the missing value flag?

["Mark Verschell" <verschell@xxxxxxxxxxxxxxxxxxxxx>]

Actually Lev, you almost had the right answer - just missed it by a little.

I am assuming that this is part of .jnl file you are calling (hence the $1 in
the first line).

So, what you want is simply:

let $2 = IF hdk[d=hdKMS] GT (-20.) THEN $1

the variable, $2, will automatically take on a bad value anytime the IF test
fails - you don't have to explicitely assign a bad value.

Mark Verschell



On Mar 17, 10:07am, Lev Tarasoff wrote:
> Subject: How do I mask out to the missing value flag?
> I'd appreciate some help with setting mask values to missing data. I
> want to mask mask out the oceanic part of data sets. I've tried a
> bunch of things including:
>
> SET VARIABLE/BAD=-1000. $1
> let $2 = IF hdk[d=hdKMS] GT (-20.) THEN $1 ELSE (-1000.)
> !hdk is the topgraphic file
>
> However, -1000 shows up in the averages when stats is issued. How do I
> assign the missing value flag to $2 when the point is to be masked
> out? (The ferret documentation seems to suggest that the missing value
> flag is represented by &SHY but I get an error with this. What is the
> symbolic representation for the missing value flag? Suggestion for
> documentation: masking out data to missing should be given as an
> explicit example, as I would think that this is a common enough need).
>-- End of excerpt from Lev Tarasoff