def test_nan_daylight_locus_function(self):
"""
Tests :func:`colour.colorimetry.illuminants.daylight_locus_function`
definition nan support.
"""
cases = [-1.0, 0.0, 1.0, -np.inf, np.inf, np.nan]
for case in cases:
daylight_locus_function(case)
def test_daylight_locus_function(self):
"""
Tests :func:`colour.colorimetry.illuminants.daylight_locus_function`
definition.
"""
self.assertAlmostEqual(
daylight_locus_function(0.31270), 0.329105129999999, places=7)
self.assertAlmostEqual(
daylight_locus_function(0.34570), 0.358633529999999, places=7)
self.assertAlmostEqual(
daylight_locus_function(0.44758), 0.408571030799999, places=7)
def test_daylight_locus_function(self):
"""
Tests :func:`colour.colorimetry.illuminants.daylight_locus_function`
definition.
"""
self.assertAlmostEqual(daylight_locus_function(0.31270),
0.329105129999999,
places=7)
self.assertAlmostEqual(daylight_locus_function(0.34570),
0.358633529999999,
places=7)
self.assertAlmostEqual(daylight_locus_function(0.44758),
0.408571030799999,
places=7)
def test_n_dimensional_daylight_locus_function(self):
"""
Tests :func:`colour.colorimetry.illuminants.daylight_locus_function`
definition n-dimensional support.
"""
x_D = np.array([0.31270])
y_D = daylight_locus_function(x_D)
x_D = np.tile(x_D, (6, 1))
y_D = np.tile(y_D, (6, 1))
np.testing.assert_almost_equal(
daylight_locus_function(x_D), y_D, decimal=7)
x_D = np.reshape(x_D, (2, 3, 1))
y_D = np.reshape(y_D, (2, 3, 1))
np.testing.assert_almost_equal(
daylight_locus_function(x_D), y_D, decimal=7)
def test_n_dimensional_daylight_locus_function(self):
"""
Tests :func:`colour.colorimetry.illuminants.daylight_locus_function`
definition n-dimensional support.
"""
x_D = np.array([0.31270])
y_D = daylight_locus_function(x_D)
x_D = np.tile(x_D, (6, 1))
y_D = np.tile(y_D, (6, 1))
np.testing.assert_almost_equal(daylight_locus_function(x_D),
y_D,
decimal=7)
x_D = np.reshape(x_D, (2, 3, 1))
y_D = np.reshape(y_D, (2, 3, 1))
np.testing.assert_almost_equal(daylight_locus_function(x_D),
y_D,
decimal=7)
def CCT_to_xy_CIE_D(CCT):
"""
Returns the *CIE xy* chromaticity coordinates of a
*CIE Illuminant D Series* from its correlated colour temperature
:math:`T_{cp}`.
Parameters
----------
CCT : numeric or array_like
Correlated colour temperature :math:`T_{cp}`.
Returns
-------
ndarray
*CIE xy* chromaticity coordinates.
Raises
------
ValueError
If the correlated colour temperature is not in appropriate domain.
References
----------
:cite:`Wyszecki2000z`
Examples
--------
>>> CCT_to_xy_CIE_D(6504.38938305) # doctest: +ELLIPSIS
array([ 0.3127077..., 0.3291128...])
"""
CCT = as_float_array(CCT)
if np.any(CCT[np.asarray(np.logical_or(CCT < 4000, CCT > 25000))]):
usage_warning(('Correlated colour temperature must be in domain '
'[4000, 25000], unpredictable results may occur!'))
CCT_3 = CCT**3
CCT_2 = CCT**2
x = np.where(
CCT <= 7000,
-4.607 * 10**9 / CCT_3 + 2.9678 * 10**6 / CCT_2 +
0.09911 * 10**3 / CCT + 0.244063,
-2.0064 * 10**9 / CCT_3 + 1.9018 * 10**6 / CCT_2 +
0.24748 * 10**3 / CCT + 0.23704,
)
y = daylight_locus_function(x)
xy = tstack([x, y])
return xy
def CCT_to_xy_CIE_D(CCT):
"""
Converts from the correlated colour temperature :math:`T_{cp}` of a
*CIE Illuminant D Series* to the chromaticity of that
*CIE Illuminant D Series* illuminant.
Parameters
----------
CCT : numeric or array_like
Correlated colour temperature :math:`T_{cp}`.
Returns
-------
ndarray
*xy* chromaticity coordinates.
Raises
------
ValueError
If the correlated colour temperature is not in appropriate domain.
References
----------
:cite:`Wyszecki2000z`
Examples
--------
>>> CCT_to_xy_CIE_D(6504.38938305) # doctest: +ELLIPSIS
array([ 0.3127077..., 0.3291128...])
"""
CCT = as_float_array(CCT)
if np.any(CCT[np.asarray(np.logical_or(CCT < 4000, CCT > 25000))]):
usage_warning(('Correlated colour temperature must be in domain '
'[4000, 25000], unpredictable results may occur!'))
x = np.where(
CCT <= 7000,
-4.607 * 10 ** 9 / CCT ** 3 + 2.9678 * 10 ** 6 / CCT ** 2 +
0.09911 * 10 ** 3 / CCT + 0.244063,
-2.0064 * 10 ** 9 / CCT ** 3 + 1.9018 * 10 ** 6 / CCT ** 2 +
0.24748 * 10 ** 3 / CCT + 0.23704,
)
y = daylight_locus_function(x)
xy = tstack([x, y])
return xy
