def test_area_statistics_cell_measure_mean(self):
"""
Test for area average of a 2D field.
The area measure is pre-loaded in the cube"""
cube = guess_bounds(self.grid, ['longitude', 'latitude'])
grid_areas = iris.analysis.cartography.area_weights(cube)
measure = iris.coords.CellMeasure(
grid_areas,
standard_name='cell_area',
units='m2',
measure='area')
self.grid.add_cell_measure(measure, range(0, measure.ndim))
result = area_statistics(self.grid, 'mean')
expected = np.array([1.])
self.assert_array_equal(result.data, expected)
def test_area_statistics_rotated(case):
"""Test `area_statistics` with data on an rotated grid."""
rotated_cube = create_rotated_grid_cube(case['data'])
operator = case['operator']
cube = area_statistics(
rotated_cube,
operator,
)
if operator != 'sum':
np.testing.assert_array_equal(cube.data, case['expected'])
else:
cube_tmp = rotated_cube.copy()
cube_tmp.remove_coord('latitude')
cube_tmp.coord('grid_latitude').rename('latitude')
cube_tmp.remove_coord('longitude')
cube_tmp.coord('grid_longitude').rename('longitude')
grid_areas = iris.analysis.cartography.area_weights(cube_tmp)
expected = np.sum(grid_areas)
np.testing.assert_array_equal(cube.data, expected)
def test_extract_region_mean(self):
"""
Test for extracting a region and performing
the area mean of a 2D field.
"""
cube = guess_bounds(self.grid, ['longitude', 'latitude'])
grid_areas = iris.analysis.cartography.area_weights(cube)
measure = iris.coords.CellMeasure(
grid_areas,
standard_name='cell_area',
units='m2',
measure='area')
self.grid.add_cell_measure(measure, range(0, measure.ndim))
region = extract_region(self.grid, 1.5, 2.5, 1.5, 2.5)
# expected outcome
expected = np.ones((2, 2))
self.assert_array_equal(region.data, expected)
result = area_statistics(region, 'mean')
expected_mean = np.array([1.])
self.assert_array_equal(result.data, expected_mean)
def test_area_statistics_variance(self):
"""Test for area average of a 2D field."""
result = area_statistics(self.grid, 'variance')
expected = np.array([0.])
self.assert_array_equal(result.data, expected)
def test_area_statistics_sum(self):
"""Test for sum of a 2D field."""
result = area_statistics(self.grid, 'sum')
grid_areas = iris.analysis.cartography.area_weights(self.grid)
expected = np.sum(grid_areas)
self.assert_array_equal(result.data, expected)
def test_area_statistics_rms(self):
"""Test for area rms of a 2D field."""
result = area_statistics(self.grid, 'rms')
expected = np.array([1.])
self.assert_array_equal(result.data, expected)
def test_area_statistics_neg_lon(self):
"""Test for area average of a 2D field."""
result = area_statistics(self.negative_grid, 'mean')
expected = np.array([1.])
self.assert_array_equal(result.data, expected)
def test_area_statistics_std_dev(self):
"""Test for area average of a 2D field."""
result = area_statistics(self.grid, 'std_dev')
expected = np.array([0.])
self.assertArrayEqual(result.data, expected)
