[ferret_users] Spatial average on irregular domain

["markus.mingel@xxxxxxxxx" <markus.mingel@xxxxxxxxx>]

Dear All,
I am trying to perform a spatial average on irregular domain. 

I know how to do that on regular domains:

let regional_ SST = SST[x=-180:180@ave,y=-30:30@ave] 

however this command does not work or curvilinear grids. Could you please 
suggest me how to compute spatial averages in such case?

Thanks for help

Regards
Markus