Removing fieldtype argument from Field constructor

[erikvansebille]

Removing fieldtype argument from Field constructor, as it's more pythonic to attach UnitConverters directly to a field?

See also #1883 (comment)

• Chose the correct base branch (main for v3 changes, v4-dev for v4 changes)

[VeckoTheGecko]

Minor edits, otherwise LGTM.

Should we be concerned with the naming of

UWind.units = parcels.tools.converters.GeographicPolar()
VWind.units = parcels.tools.converters.Geographic()

? Previously it might have been easier to identify that VWind would be of field type V, whereas now its probably not as clear to the user that it needs a Geographic converter and not a GeographicPolar converter. Perhaps this would just be something to keep an eye on moving forward, that we can revisit the naming/how to specify these unit converters.

[VeckoTheGecko]

I also added a setter for Field.units

[erikvansebille]

Minor edits, otherwise LGTM.

Should we be concerned with the naming of

UWind.units = parcels.tools.converters.GeographicPolar()
VWind.units = parcels.tools.converters.Geographic()

? Previously it might have been easier to identify that VWind would be of field type V, whereas now its probably not as clear to the user that it needs a Geographic converter and not a GeographicPolar converter. Perhaps this would just be something to keep an eye on moving forward, that we can revisit the naming/how to specify these unit converters.

Good point that these names may be confusing. Maybe the names DegreeToMeterLongitude and DegreeToMeterLatitude make more sense?