Unreliable Field.fieldtype constant

[VeckoTheGecko]

In the Field constructor:

Parcels/parcels/field.py

Lines 106 to 107 in 5fff42c

	fieldtype : str
	Type of Field to be used for UnitConverter (either 'U', 'V', 'Kh_zonal', 'Kh_meridional' or None)

However the underlying behaviour looks to be a bit different.

Parcels/parcels/field.py

Line 198 in 5fff42c

self.fieldtype = self.name if fieldtype is None else fieldtype

This leads to strange stuff like:

>>> field = Field("newfld", fieldset.U.data, lon=fieldset.U.lon, lat=fieldset.U.lat)
>>> fieldset.add_field(field)
>>> print(fieldset.newfld.fieldtype)
"newfld"

I don't think this is a bug per-se (doubt it affects interpolation), but it is worth cleaning up to be None in this case.

[VeckoTheGecko]

This will likely be moved to the internal API/scheduled for removal anyway. .units already provides unit information

[erikvansebille]

Good catch; yes this can certainly be cleaned up!