def test_extract_point__single_linear(self):
"""Test linear interpolation when extracting a single point"""
point = extract_point(self.cube, 2.1, 2.1, scheme='linear')
self.assertEqual(point.shape, (3, ))
np.testing.assert_allclose(point.data, [5.5, 21.5, 37.5])
# Exactly centred between grid points.
point = extract_point(self.cube, 2.5, 2.5, scheme='linear')
self.assertEqual(point.shape, (3, ))
np.testing.assert_allclose(point.data, [7.5, 23.5, 39.5])
# On a (edge) grid point.
point = extract_point(self.cube, 4, 4, scheme='linear')
self.assertEqual(point.shape, (3, ))
np.testing.assert_allclose(point.data, [15, 31, 47])
# Test two points outside the valid area.
# These should be masked, since we set up the interpolation
# schemes that way.
point = extract_point(self.cube, -1, -1, scheme='linear')
self.assertEqual(point.shape, (3, ))
masked = np.ma.array([np.nan] * 3, mask=True)
self.assert_array_equal(point.data, masked)
point = extract_point(self.cube, 30, 30, scheme='linear')
self.assertEqual(point.shape, (3, ))
self.assert_array_equal(point.data, masked)
def test_extract_point__multiple_nearest(self):
"""Test nearest match for an array of one coordinate"""
point = extract_point(self.cube, [1, 1.1, 1.5, 1.501, 2, 4],
2,
scheme='nearest')
self.assertEqual(point.shape, (3, 6))
self.assertEqual(
['air_pressure', 'latitude'],
[coord.standard_name for coord in point.coords(dim_coords=True)])
np.testing.assert_allclose(
point.data, [[1, 1, 1, 5, 5, 13], [17, 17, 17, 21, 21, 29],
[33, 33, 33, 37, 37, 45]])
point = extract_point(self.cube,
4, [1, 1.1, 1.5, 1.501, 2, 4],
scheme='nearest')
self.assertEqual(point.shape, (3, 6))
self.assertEqual(
['air_pressure', 'longitude'],
[coord.standard_name for coord in point.coords(dim_coords=True)])
np.testing.assert_allclose(
point.data, [[12, 12, 12, 13, 13, 15], [28, 28, 28, 29, 29, 31],
[44, 44, 44, 45, 45, 47]])
point = extract_point(self.cube, [0, 10], 3, scheme='nearest')
masked = np.ma.array(np.empty((3, 2), dtype=np.float), mask=True)
self.assertEqual(point.shape, (3, 2))
self.assert_array_equal(point.data, masked)
point = extract_point(self.cube, 2, [0, 10], scheme='nearest')
self.assertEqual(point.shape, (3, 2))
self.assert_array_equal(point.data, masked)
def test_extract_point__multiple_both_nearest(self):
"""Test for both latitude and longitude arrays, with nearest match"""
point = extract_point(self.cube, [0, 1.1, 1.5, 1.51, 4, 5],
[0, 1.1, 1.5, 1.51, 4, 5],
scheme='nearest')
self.assertEqual(point.data.shape, (3, 6, 6))
result = np.ma.array(np.empty((3, 6, 6), dtype=np.float), mask=True)
result[0, 1, 1:5] = [0.0, 0.0, 1.0, 3.0]
result[0, 2, 1:5] = [0.0, 0.0, 1.0, 3.0]
result[0, 3, 1:5] = [4.0, 4.0, 5.0, 7.0]
result[0, 4, 1:5] = [12.0, 12.0, 13.0, 15.0]
result[1, 1, 1:5] = [16.0, 16.0, 17.0, 19.0]
result[1, 2, 1:5] = [16.0, 16.0, 17.0, 19.0]
result[1, 3, 1:5] = [20.0, 20.0, 21.0, 23.0]
result[1, 4, 1:5] = [28.0, 28.0, 29.0, 31.0]
result[2, 1, 1:5] = [32.0, 32.0, 33.0, 35.0]
result[2, 2, 1:5] = [32.0, 32.0, 33.0, 35.0]
result[2, 3, 1:5] = [36.0, 36.0, 37.0, 39.0]
result[2, 4, 1:5] = [44.0, 44.0, 45.0, 47.0]
result.mask[:, 1:5, 1:5] = False
np.testing.assert_allclose(point.data, result)
def test_extract_point__multiple_both_linear(self):
"""Test for both latitude and longitude arrays, with
linear interpolation"""
point = extract_point(self.cube, [0, 1.1, 1.5, 1.51, 4, 5],
[0, 1.1, 1.5, 1.51, 4, 5],
scheme='linear')
self.assertEqual(point.data.shape, (3, 6, 6))
result = np.ma.array(np.empty((3, 6, 6), dtype=np.float), mask=True)
result[0, 1, 1:5] = [0.5, 0.9, 0.91, 3.4]
result[0, 2, 1:5] = [2.1, 2.5, 2.51, 5.0]
result[0, 3, 1:5] = [2.14, 2.54, 2.55, 5.04]
result[0, 4, 1:5] = [12.1, 12.5, 12.51, 15.0]
result[1, 1, 1:5] = [16.5, 16.9, 16.91, 19.4]
result[1, 2, 1:5] = [18.10, 18.5, 18.51, 21.0]
result[1, 3, 1:5] = [18.14, 18.54, 18.55, 21.04]
result[1, 4, 1:5] = [28.1, 28.5, 28.51, 31.0]
result[2, 1, 1:5] = [32.5, 32.9, 32.91, 35.4]
result[2, 2, 1:5] = [34.1, 34.5, 34.51, 37]
result[2, 3, 1:5] = [34.14, 34.54, 34.55, 37.04]
result[2, 4, 1:5] = [44.1, 44.5, 44.51, 47]
# Unmask the inner area of the result array.
# The outer edges of the extracted points are outside the cube
# grid, and should thus be masked.
result.mask[:, 1:5, 1:5] = False
np.testing.assert_allclose(point.data, result)
def test_extract_point__multiple_linear(self):
"""Test linear interpolation for an array of one coordinate"""
# Test points on the grid edges, on a grid point, halfway and
# one in between.
coords = self.cube.coords(dim_coords=True)
print([coord.standard_name for coord in coords])
point = extract_point(self.cube, [1, 1.1, 1.5, 2, 4],
2,
scheme='linear')
self.assertEqual(point.shape, (3, 5))
# Longitude is not a dimension coordinate anymore.
self.assertEqual(
['air_pressure', 'latitude'],
[coord.standard_name for coord in point.coords(dim_coords=True)])
np.testing.assert_allclose(
point.data, [[1, 1.4, 3, 5, 13], [17, 17.4, 19., 21., 29],
[33, 33.4, 35, 37, 45]])
point = extract_point(self.cube,
4, [1, 1.1, 1.5, 2, 4],
scheme='linear')
self.assertEqual(point.shape, (3, 5))
self.assertEqual(
['air_pressure', 'longitude'],
[coord.standard_name for coord in point.coords(dim_coords=True)])
np.testing.assert_allclose(
point.data, [[12, 12.1, 12.5, 13, 15], [28, 28.1, 28.5, 29, 31],
[44, 44.1, 44.5, 45, 47]])
# Test latitude and longitude points outside the grid.
# These should all be masked.
coords = self.cube.coords(dim_coords=True)
point = extract_point(self.cube, [0, 10], 3, scheme='linear')
self.assertEqual(point.shape, (3, 2))
masked = np.ma.array(np.empty((3, 2), dtype=np.float), mask=True)
self.assert_array_equal(point.data, masked)
coords = self.cube.coords(dim_coords=True)
point = extract_point(self.cube, 2, [0, 10], scheme='linear')
coords = point.coords(dim_coords=True)
self.assertEqual(point.shape, (3, 2))
self.assert_array_equal(point.data, masked)
def test_extract_point__single_nearest(self):
"""Test nearest match when extracting a single point"""
point = extract_point(self.cube, 2.1, 2.1, scheme='nearest')
self.assertEqual(point.shape, (3, ))
np.testing.assert_allclose(point.data, [5, 21, 37])
point = extract_point(self.cube, 4, 4, scheme='nearest')
self.assertEqual(point.shape, (3, ))
np.testing.assert_allclose(point.data, [15, 31, 47])
# Test two points outside the valid area
point = extract_point(self.cube, -1, -1, scheme='nearest')
self.assertEqual(point.shape, (3, ))
masked = np.ma.array(np.empty(3, dtype=np.float), mask=True)
self.assert_array_equal(point.data, masked)
point = extract_point(self.cube, 30, 30, scheme='nearest')
self.assertEqual(point.shape, (3, ))
self.assert_array_equal(point.data, masked)
def run_extract_point(
cube,
settings: typing.Dict,
**kwargs,
):
latitude = settings["latitude"]
longitude = settings["longitude"]
scheme = settings["scheme"]
result = extract_point(
cube,
latitude=latitude,
longitude=longitude,
scheme=scheme,
)
return result
def test_extract_point(self):
dummy = mock.sentinel.dummy
scheme = 'linear'
result = extract_point(self.src_cube, dummy, dummy, scheme)
self.assertEqual(result, self.point_cube)
def test_extract_point_interpolation_schemes(self):
dummy = mock.sentinel.dummy
for scheme in self.schemes:
result = extract_point(self.src_cube, dummy, dummy, scheme)
self.assertEqual(result, self.point_cube)
def test_invalid_scheme__unknown(self):
dummy = mock.sentinel.dummy
emsg = "Unknown interpolation scheme, got 'non-existent'"
with self.assertRaisesRegex(ValueError, emsg):
extract_point(dummy, dummy, dummy, 'non-existent')
