>With temp[x=@ave,y=@ave], Ferret does compute the area weighted average if the horizontal axes are longitude
>and latitude.
So in my example the problem is that x and y axis aren't longitude and latitude. Fortunately there are data with names ULONG and ULAT which are lat and log. So the problem is how to tell ferret that x ais should be ULONG and y axis ULAT and then use @AVE to compute weighted average,