def test_second_derivative_2d(deriv_2d_data):
"""Test second_derivative with a full 2D array."""
df2_dx2 = second_derivative(deriv_2d_data.f, x=deriv_2d_data.x, axis=1)
assert_array_almost_equal(df2_dx2,
np.ones_like(deriv_2d_data.f) * (2 * deriv_2d_data.a), 5)
df2_dy2 = second_derivative(deriv_2d_data.f, x=deriv_2d_data.y, axis=0)
assert_array_almost_equal(df2_dy2,
np.ones_like(deriv_2d_data.f) * (2 * deriv_2d_data.b), 5)
def test_second_derivative_2d(deriv_2d_data):
"""Test second_derivative with a full 2D array."""
df2_dx2 = second_derivative(deriv_2d_data.f, x=deriv_2d_data.x, axis=1)
assert_array_almost_equal(df2_dx2,
np.ones_like(deriv_2d_data.f) * (2 * deriv_2d_data.a), 5)
df2_dy2 = second_derivative(deriv_2d_data.f, x=deriv_2d_data.y, axis=0)
assert_array_almost_equal(df2_dy2,
np.ones_like(deriv_2d_data.f) * (2 * deriv_2d_data.b), 5)
def test_second_derivative(deriv_1d_data):
"""Test second_derivative with a simple 1D array."""
d2v_dx2 = second_derivative(deriv_1d_data.values, x=deriv_1d_data.x)
# Worked by hand
truth = np.ones_like(deriv_1d_data.values) * 0.2133333 * units('delta_degC/cm**2')
assert_array_almost_equal(d2v_dx2, truth, 5)
def test_second_derivative(deriv_1d_data):
"""Test second_derivative with a simple 1D array."""
d2v_dx2 = second_derivative(deriv_1d_data.values, x=deriv_1d_data.x)
# Worked by hand
truth = np.ones_like(deriv_1d_data.values) * 0.2133333 * units('delta_degC/cm**2')
assert_array_almost_equal(d2v_dx2, truth, 5)
def test_second_derivative_xarray_lonlat(test_da_lonlat):
"""Test second derivative with an xarray.DataArray on a lonlat grid."""
deriv = second_derivative(test_da_lonlat, axis='lat')
# Build the xarray of the desired values
partial = xr.DataArray(np.array(
[1.67155420e-14, 1.67155420e-14, 1.74268211e-14, 1.74268211e-14]),
coords=(('lat', test_da_lonlat['lat']), ))
_, truth = xr.broadcast(test_da_lonlat, partial)
truth.coords['crs'] = test_da_lonlat['crs']
truth.attrs['units'] = 'kelvin / meter^2'
xr.testing.assert_allclose(deriv, truth)
assert deriv.metpy.units == truth.metpy.units
def test_second_derivative_xarray_lonlat(test_da_lonlat):
"""Test second derivative with an xarray.DataArray on a lonlat grid."""
deriv = second_derivative(test_da_lonlat, axis='lat')
# Build the xarray of the desired values
partial = xr.DataArray(
np.array([1.67155420e-14, 1.67155420e-14, 1.74268211e-14, 1.74268211e-14]),
coords=(('lat', test_da_lonlat['lat']),)
)
_, truth = xr.broadcast(test_da_lonlat, partial)
truth.coords['crs'] = test_da_lonlat['crs']
truth.attrs['units'] = 'kelvin / meter^2'
xr.testing.assert_allclose(deriv, truth)
assert deriv.metpy.units == truth.metpy.units
def test_second_derivative_scalar_delta():
"""Test second_derivative with a scalar passed for a delta."""
df_dx = second_derivative(np.arange(3), delta=1)
assert_array_almost_equal(df_dx, np.array([0., 0., 0.]), 6)
def test_second_derivative_too_small(deriv_1d_data):
"""Test second_derivative with too small an array."""
with pytest.raises(ValueError):
second_derivative(deriv_1d_data.values[None, :].T, x=deriv_1d_data.x, axis=1)
def test_second_derivative_scalar_delta():
"""Test second_derivative with a scalar passed for a delta."""
df_dx = second_derivative(np.arange(3), delta=1)
assert_array_almost_equal(df_dx, np.array([0., 0., 0.]), 6)
def test_second_derivative_too_small(deriv_1d_data):
"""Test second_derivative with too small an array."""
with pytest.raises(ValueError):
second_derivative(deriv_1d_data.values[None, :].T, x=deriv_1d_data.x, axis=1)
