Re: [ferret_users] how to do differential in ferret?

[Ryo Furue <furue@xxxxxxxxxx>]

Hi Arnold,

> I know we can do differential in x,y,z or t but how about to other
> variables?
>
> Say something like du/dv, du/dtemp ?

Suppose u and temp are two dimensional fields: u(x,y), temp(x,y).
Then, there is no unique definition of du/dtemp because
the ratio of du to dtemp depends on the direction of taking
the differentials.  If you know which direction to take the differentials,
then you want something like,

   let du_dtemp = u[x=@DCC] / temp[x=@DCC]

After some algebra, you can also compute differentials
in arbitrary directions, I guess, but I haven't thought hard
about it.

Cheers,

Ryo