def test_reversed_points(self):
cube1, cube2 = self.SetUpReversed()
with self.assertRaises(ValueError):
multiply(cube1, cube2)
def test_no_match(self):
cube1, cube2 = self.SetUpNonMatching()
with self.assertRaises(ValueError):
multiply(cube1, cube2)
def test_reversed_points(self):
cube1, cube2 = self.SetUpReversed()
with self.assertRaises(ValueError):
multiply(cube1, cube2)
def apply_gridded_lapse_rate(temperature, lapse_rate, source_orog, dest_orog):
"""
Function to apply a lapse rate adjustment to temperature data forecast
at "source_orog" heights, to be applicable at "dest_orog" heights.
Args:
temperature (iris.cube.Cube):
Input temperature field to be adjusted
lapse_rate (iris.cube.Cube):
Cube of pre-calculated lapse rates (units modified in place), which
must match the temperature cube
source_orog (iris.cube.Cube):
2D cube of source orography heights (units modified in place)
dest_orog (iris.cube.Cube):
2D cube of destination orography heights (units modified in place)
Returns:
iris.cube.Cube:
Lapse-rate adjusted temperature field
"""
# check dimensions and coordinates match on input cubes
for crd in temperature.coords(dim_coords=True):
try:
if crd != lapse_rate.coord(crd.name()):
raise ValueError(
'Lapse rate cube coordinate "{}" does not match '
'temperature cube coordinate'.format(crd.name()))
except CoordinateNotFoundError:
raise ValueError('Lapse rate cube has no coordinate '
'"{}"'.format(crd.name()))
if not spatial_coords_match(temperature, source_orog):
raise ValueError('Source orography spatial coordinates do not match '
'temperature grid')
if not spatial_coords_match(temperature, dest_orog):
raise ValueError(
'Destination orography spatial coordinates do not match '
'temperature grid')
# calculate height difference (in m) on which to adjust
source_orog.convert_units('m')
dest_orog.convert_units('m')
orog_diff = (
next(
dest_orog.slices(
[dest_orog.coord(axis='y'),
dest_orog.coord(axis='x')])) -
next(
source_orog.slices(
[source_orog.coord(axis='y'),
source_orog.coord(axis='x')])))
# convert lapse rate cube to K m-1
lapse_rate.convert_units('K m-1')
# adjust temperatures
adjusted_temperature = []
for lrsubcube, tempsubcube in zip(
lapse_rate.slices(
[lapse_rate.coord(axis='y'),
lapse_rate.coord(axis='x')]),
temperature.slices(
[temperature.coord(axis='y'),
temperature.coord(axis='x')])):
# calculate temperature adjustment in K
adjustment = multiply(orog_diff, lrsubcube)
# apply adjustment to each spatial slice of the temperature cube
newcube = tempsubcube.copy()
newcube.convert_units('K')
newcube.data += adjustment.data
adjusted_temperature.append(newcube)
return iris.cube.CubeList(adjusted_temperature).merge_cube()
def test_no_match(self):
cube1, cube2 = self.SetUpNonMatching()
with self.assertRaises(ValueError):
multiply(cube1, cube2)
