Re: [ferret_users] set a single point to be zero

[Andrew Wittenberg <Andrew.Wittenberg@xxxxxxxx>]

On Wed, 14 Mar 2007, Jaclyn Brown wrote:

> I have a 4-D data file in x,y,z, t and I'd like to change one x-y point to
> zero to make it a land point.
>
> ie. uvel(i=59,j=93)=0
>
> I can't find a ferret command that will let me do this.

Hi Jaci,

You can use a "masking expression" like this:

   let uvel_new = IF i EQ 59 AND j EQ 93 THEN 0 ELSE uvel

See the user's guide:

http://ferret.wrc.noaa.gov/Ferret/Documentation/Users_Guide/current/Chapter3_Variables_and_Expressions.htm#_VPINDEXENTRY_534

Cheers,

Andrew