Hi Lívia,
[. . .]
> Dear fellows, I'm trying to isolate the velocity field of a water
> parcel through a density interval.
> yes? fill uvelThis error seems to be from your "z=0:5500@int". I don't think there
>
> **ERROR: command syntax: Unknown transformation:5500
> Use SHOW TRANSFORMS for a list of legal transformations
is a transformation "@INT".
I'm not quite sure what do you mean by "isolate the velocity field".
With this definition
your water1 is the same as u[d=3] only where 1027.6 < sigma <= 1027.8
> let water1 = if (sigma ge 1027.6 and sigma le 1027.8) then u[d=3]
and it's undefined elsewhere.
If you want to integrate the velocity field within this density class,
probably this is what you want:
let uvel = water1[z=0:5500@din]
"@DIN" is a definite integral. I'm not sure whether this method
has enough accuracy for your purpose; because in this calculation
there is no interpolation but the gridboxes with density values
outside the range are simply ignored in the integration.
Ryo