davidhassell
commented
10 months ago I've just been checking the time subspacing syntax, and thought I'd share for the record. cf.cellwi is probably the query of choice here (and for the X and Y axes, too).
>>> import cf
>>> f = cf.example_field(2)
>>> print(f)
Field: air_potential_temperature (ncvar%air_potential_temperature)
------------------------------------------------------------------
Data : air_potential_temperature(time(36), latitude(5), longitude(8)) K
Cell methods : area: mean
Dimension coords: time(36) = [1959-12-16 12:00:00, ..., 1962-11-16 00:00:00]
: latitude(5) = [-75.0, ..., 75.0] degrees_north
: longitude(8) = [22.5, ..., 337.5] degrees_east
: air_pressure(1) = [850.0] hPa
>>> print(f.subspace(T=cf.cellwi(cf.dt(1959, 12, 1), cf.dt(1960, 5, 1))))
Field: air_potential_temperature (ncvar%air_potential_temperature)
------------------------------------------------------------------
Data : air_potential_temperature(time(5), latitude(5), longitude(8)) K
Cell methods : area: mean
Dimension coords: time(5) = [1959-12-16 12:00:00, ..., 1960-04-16 00:00:00]
: latitude(5) = [-75.0, ..., 75.0] degrees_north
: longitude(8) = [22.5, ..., 337.5] degrees_east
: air_pressure(1) = [850.0] hPaIn this example cf.wi would give the same result but that is not always the case, since cf.wi queries representative cell values, rather than bounds extents.
Implement subspacing for axes queries (i.e. subset of months over time) Important ones are time, latitude and longitude so just do those.