def test_clearsky_index():
ghi = np.array([-1., 0., 1., 500., 1000., np.nan])
ghi_measured, ghi_modeled = np.meshgrid(ghi, ghi)
# default max_clearsky_index
with np.errstate(invalid='ignore', divide='ignore'):
out = irradiance.clearsky_index(ghi_measured, ghi_modeled)
expected = np.array([[1., 0., 0., 0., 0., np.nan],
[0., 0., 0., 0., 0., np.nan],
[0., 0., 1., 2., 2., np.nan],
[0., 0., 0.002, 1., 2., np.nan],
[0., 0., 0.001, 0.5, 1., np.nan],
[np.nan, np.nan, np.nan, np.nan, np.nan, np.nan]])
assert_allclose(out, expected, atol=0.001)
# specify max_clearsky_index
with np.errstate(invalid='ignore', divide='ignore'):
out = irradiance.clearsky_index(ghi_measured,
ghi_modeled,
max_clearsky_index=1.5)
expected = np.array([[1., 0., 0., 0., 0., np.nan],
[0., 0., 0., 0., 0., np.nan],
[0., 0., 1., 1.5, 1.5, np.nan],
[0., 0., 0.002, 1., 1.5, np.nan],
[0., 0., 0.001, 0.5, 1., np.nan],
[np.nan, np.nan, np.nan, np.nan, np.nan, np.nan]])
assert_allclose(out, expected, atol=0.001)
# scalars
out = irradiance.clearsky_index(10, 1000)
expected = 0.01
assert_allclose(out, expected, atol=0.001)
# series
times = pd.date_range(start='20180601', periods=2, freq='12H')
ghi_measured = pd.Series([100, 500], index=times)
ghi_modeled = pd.Series([500, 1000], index=times)
out = irradiance.clearsky_index(ghi_measured, ghi_modeled)
expected = pd.Series([0.2, 0.5], index=times)
assert_series_equal(out, expected)
def check_poa_clearsky(poa_global, poa_clearsky, kt_max=1.1):
"""
Flags plane of array irradiance values greater than clearsky values.
Parameters
----------
poa_global : Series
Plane of array irradiance in W/m^2
poa_clearsky : Series
Plane of array irradiance under clear sky conditions, in W/m^2
kt_max : float
maximum allowed ratio of poa_global to poa_clearsky
Returns
-------
flags : Series
True if poa_global is less than or equal to clear sky value.
"""
kt = clearsky_index(poa_global, poa_clearsky, max_clearsky_index=np.Inf)
flags = _check_limits(kt, ub=kt_max, ub_le=True)
return flags
def check_ghi_clearsky(ghi, ghi_clearsky, kt_max=1.1):
"""
Flags GHI values greater than clearsky values.
Parameters
----------
ghi : Series
Global horizontal irradiance in W/m^2
ghi_clearsky : Series
Global horizontal irradiance in W/m^2 under clear sky conditions
kt_max : float
maximum clearness index that defines when ghi exceeds clear-sky value.
Returns
-------
flags : Series
True if ghi is less than or equal to clear sky value.
"""
kt = clearsky_index(ghi, ghi_clearsky, max_clearsky_index=np.Inf)
flags = _check_limits(kt, ub=kt_max, ub_le=True)
return flags