Re: regriding, masks etc

[Ansley Manke <ansley@xxxxxxxxxxxxx>]

Hi Josef,
A bit more on this topic, thanks to Steve Hankin:
The general answer on regridding is that g=@AVE is usually preferable
when going from fine to coarse  -- no transformation (interpolation) when
going from coarse to fine grids.

The case of a coastline mask is one where the grid cells contain boolean
(yes or no), so neither averaging nor interpolation makes a great deal
of sense. The user needs to decide what is the appropriate behavior
first -- worrying about Ferret syntax afterwards. Look at the regridding
transformations g=@MIN and g=@MAX.  When going from fine to
coarse these become tools so that. if any (fine) point has elevation gt 0
(land) then @MAX will flag it as land. If any point has water then @MIN
will flag the result as  water.

Ansley Manke