Re: [ferret_users] area average only for upwar motions

[Ansley Manke <ansley.b.manke@xxxxxxxx>]

Hi everyone,
Andrew's right on, I just to add that the User's Guide calls this technique "masking". It's a powerful way to apply a function or transformation over a region or other subset of data.

Ansley

Andrew Wittenberg wrote:

On Tue, 7 Feb 2006, Seon Tae wrote:

  

I want to make an area-avearge of a quantity like vertical velocity.
But, i want to do it only for upward motion. I mean, i want to exclude
downward motion in doing an area-average
Do you guys help me with it?
    

! a new variable, with w<=0 set to missing
let w_up = IF w GT 0 THEN w

! average is computed only over the valid points
let w_up_ave = w_up[x=@ave,y=@ave]

Andrew