def test_histogram_dnb(self):
"""Test the 'histogram_dnb' compositor."""
import dask.array as da
import numpy as np
import xarray as xr
from pyresample.geometry import AreaDefinition
from satpy.composites.viirs import HistogramDNB
rows = 5
cols = 10
area = AreaDefinition('test', 'test', 'test', {
'proj': 'eqc',
'lon_0': 0.0,
'lat_0': 0.0
}, cols, rows, (-20037508.34, -10018754.17, 20037508.34, 10018754.17))
comp = HistogramDNB('histogram_dnb',
prerequisites=('dnb', ),
standard_name='toa_outgoing_radiance_per_'
'unit_wavelength')
dnb = np.zeros((rows, cols)) + 0.25
dnb[3, :] += 0.25
dnb[4:, :] += 0.5
dnb = da.from_array(dnb, chunks=25)
c01 = xr.DataArray(dnb,
dims=('y', 'x'),
attrs={
'name': 'DNB',
'area': area
})
# data changes by row, sza changes by col for testing
sza = np.zeros((rows, cols)) + 70.0
sza[:, 3] += 20.0
sza[:, 4:] += 45.0
sza = da.from_array(sza, chunks=25)
c02 = xr.DataArray(sza,
dims=('y', 'x'),
attrs={
'name': 'solar_zenith_angle',
'area': area
})
res = comp((c01, c02))
self.assertIsInstance(res, xr.DataArray)
self.assertIsInstance(res.data, da.Array)
self.assertEqual(res.attrs['name'], 'histogram_dnb')
self.assertEqual(res.attrs['standard_name'], 'equalized_radiance')
data = res.compute()
unique_values = np.unique(data)
np.testing.assert_allclose(unique_values, [0.5994, 0.7992, 0.999],
rtol=1e-3)
def test_histogram_dnb(self, c01, c02):
"""Test the 'histogram_dnb' compositor."""
from satpy.composites.viirs import HistogramDNB
comp = HistogramDNB('histogram_dnb',
prerequisites=('dnb', ),
standard_name='toa_outgoing_radiance_per_'
'unit_wavelength')
res = comp((c01, c02))
assert isinstance(res, xr.DataArray)
assert isinstance(res.data, da.Array)
assert res.attrs['name'] == 'histogram_dnb'
assert res.attrs['standard_name'] == 'equalized_radiance'
data = res.compute()
unique_values = np.unique(data)
np.testing.assert_allclose(unique_values, [0.5994, 0.7992, 0.999],
rtol=1e-3)