def test_cfunits_conform(self):
units_kelvin = get_units_object('kelvin')
# Conversion of celsius units to kelvin.
attrs = {k: 1 for k in NETCDF_ATTRIBUTES_TO_REMOVE_ON_VALUE_CHANGE}
var = Variable(name='tas', units='celsius', value=self.value, attrs=attrs)
self.assertEqual(len(var.attrs), 4)
var.cfunits_conform(units_kelvin)
self.assertNumpyAll(var.value, np.ma.array([278.15] * 3))
self.assertEqual(var.cfunits, units_kelvin)
self.assertEqual(var.units, 'kelvin')
self.assertEqual(len(var.attrs), 0)
# If there are no units associated with a variable, conforming the units should fail.
var = Variable(name='tas', units=None, value=self.value)
with self.assertRaises(NoUnitsError):
var.cfunits_conform(units_kelvin)
# Conversion should fail for nonequivalent units.
var = Variable(name='tas', units='kelvin', value=self.value)
with self.assertRaises(ValueError):
var.cfunits_conform(get_units_object('grams'))
# The data type should always be updated to match the output from CF units backend.
av = Variable(value=np.array([4, 5, 6]), dtype=int)
self.assertEqual(av.dtype, np.dtype(int))
with self.assertRaises(NoUnitsError):
av.cfunits_conform('K')
av.units = 'celsius'
av.cfunits_conform('K')
self.assertIsNone(av._dtype)
self.assertEqual(av.dtype, av.value.dtype)
def test_conform(self):
## conversion of celsius units to kelvin
var = Variable(name='tas',units='celsius',value=self.value)
var.cfunits_conform(Units('kelvin'))
self.assertNumpyAll(var.value,np.ma.array([278.15]*3))
self.assertEqual(var.cfunits,Units('kelvin'))
self.assertEqual(var.units,'kelvin')
def test_cfunits_conform(self):
# conversion of celsius units to kelvin
attrs = {k: 1 for k in NETCDF_ATTRIBUTES_TO_REMOVE_ON_VALUE_CHANGE}
var = Variable(name='tas', units='celsius', value=self.value, attrs=attrs)
self.assertEqual(len(var.attrs), 2)
var.cfunits_conform(Units('kelvin'))
self.assertNumpyAll(var.value, np.ma.array([278.15] * 3))
self.assertEqual(var.cfunits, Units('kelvin'))
self.assertEqual(var.units, 'kelvin')
self.assertEqual(len(var.attrs), 0)
# if there are no units associated with a variable, conforming the units should fail
var = Variable(name='tas', units=None, value=self.value)
with self.assertRaises(NoUnitsError):
var.cfunits_conform(Units('kelvin'))
# conversion should fail for nonequivalent units
var = Variable(name='tas', units='kelvin', value=self.value)
with self.assertRaises(ValueError):
var.cfunits_conform(Units('grams'))
# the data type should always be updated to match the output from cfunits
av = FakeAbstractValueVariable(value=np.array([4, 5, 6]), dtype=int)
self.assertEqual(av.dtype, np.dtype(int))
with self.assertRaises(NoUnitsError):
av.cfunits_conform('K')
av.units = 'celsius'
av.cfunits_conform('K')
self.assertIsNone(av._dtype)
self.assertEqual(av.dtype, av.value.dtype)
# calendar can be finicky - those need to be stripped from the string conversion
conform_units_to = Units('days since 1949-1-1', calendar='standard')
units = Units('days since 1900-1-1', calendar='standard')
av = FakeAbstractValueVariable(value=np.array([4000, 5000, 6000]), units=units,
conform_units_to=conform_units_to)
self.assertEqual(av.units, 'days since 1949-1-1')
def test_cfunits_conform_masked_array(self):
# assert mask is respected by inplace unit conversion
value = np.ma.array(data=[5, 5, 5], mask=[False, True, False])
var = Variable(name='tas', units=Units('celsius'), value=value)
var.cfunits_conform(Units('kelvin'))
self.assertNumpyAll(np.ma.array([278.15, 278.15, 278.15], mask=[False, True, False]), var.value)
def test_conform_no_units(self):
## if there are no units associate with a variable, conforming the units
## should fail
var = Variable(name='tas',units=None,value=self.value)
with self.assertRaises(NoUnitsError):
var.cfunits_conform(Units('kelvin'))
def test_conform_nonequivalent_units(self):
## conversion should fail for nonequivalent units
var = Variable(name='tas',units='kelvin',value=self.value)
with self.assertRaises(ValueError):
var.cfunits_conform(Units('grams'))
