Re: [idvusers] IDV formula for gradient of scalar field

Hi Stu, Don,

Can the same be used on for gradient in 3 dimensions ?


-----Original Message-----
From: idvusers-bounces@xxxxxxxxxxxxxxxx
[mailto:idvusers-bounces@xxxxxxxxxxxxxxxx] On Behalf Of Don Murray
Sent: Friday, May 01, 2009 9:06 PM
To: Stuart Wier
Cc: IDV Users
Subject: Re: [idvusers] IDV formula for gradient of scalar field

Hi Stu-

Stuart Wier wrote:
> I need to make an IDV formula to make the gradient of a 2d scalar 
> field (a new 2d vector field), and also the magnitude of the gradient 
> as a new scalar field. Anyone know how to do that offhand?

You can use the grad(S) python procedure in the module to
compute the gradient.  Use the mag(V) procedure to compute the magnitude
of the resulting vector:


You can use the Grid->Define a grid diagnostic Formula to try this on
the fly, or create a formula.

All the jython procedures are documented at:

(I just noticed that the mag function on that page is not formatted
correctly.  I'll fix that for a future release).

Don Murray                               UCAR Unidata Program
dmurray@xxxxxxxxxxxxxxxx                        P.O. Box 3000
(303) 497-8628                              Boulder, CO 80307

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