setFillValue

Applies a spatial mask to grid data by copying fill values from a 2D reference mask.

Signature

call setFillValue(mask, idata)
call setFillValue(mask, idata, num)   ! optional: filter by value

Parameter	Intent	Type	Description
mask	in	FPL 2D type	Reference mask (first argument)
idata	inout	FPL 2D/3D/4D type	Data to be masked (second argument)
num	in	integer, optional	When present, masks cells where mask%ncdata /= num instead of using FillValue

Behavior

Without num: For every (i,j) where mask%ncdata(i,j) == mask%FillValue:

• 2D: idata%ncdata(i,j) = idata%FillValue
• 3D: idata%ncdata(i,j,t) = idata%FillValue for all t
• 4D: idata%ncdata(i,j,t,l) = idata%FillValue for all t,l

With num: For every (i,j) where mask%ncdata(i,j) /= num, the data is set to FillValue. Where mask%ncdata(i,j) == num and idata already has FillValue, it is set to 0.

caution

The mask and data grids must have the same spatial dimensions (nlons × nlats). The mask is always 2D regardless of the data dimensionality.

Type Combinations

The data and mask can have different numeric types. FPL provides specific procedures for every combination (e.g., setfvalue3d_floatbyte_llf_ti for float data with byte mask).

Example

type(nc3d_float_llf_ti) :: temperature
type(nc2d_byte_llf)     :: land_mask

call readgrid("temperature.nc", temperature)
call readgrid("land_mask.nc", land_mask)

! Mask ocean cells (where land_mask is FillValue)
call setFillValue(land_mask, temperature)

! Or filter by a specific mask value (e.g., state code 18)
! call setFillValue(land_mask, temperature, 18)

call writegrid("temperature_land_only.nc", temperature)

call dealloc(temperature)
call dealloc(land_mask)