anomalies

[Wendy Wang <wwang@xxxxxxxxxxxxx>]

Hi ferret_users,

I try to get anomalies:

yes? let h_time=h[t=16-jan-1971:16-dec-1980]
yes? let h_clim=h_time[gt=month_reg@mod]
yes? let h_a=h-h_clim[gt=cl@asn]

It works fine with original data. But it seems not work with those
data averaged or integrated over space:

yes? list h_a
**ERROR: unknown defining grid: GT=Cl@ASN

Does anybody know why? Thanks in advance.

Wendy Wang