colour.sd_rayleigh_jeans#

colour.sd_rayleigh_jeans(temperature: float, shape: colour.colorimetry.spectrum.SpectralShape = SPECTRAL_SHAPE_DEFAULT) → colour.colorimetry.spectrum.SpectralDistribution[source]#

Return the spectral distribution of the planckian radiator for given temperature \(T[K]\) with values in watts per steradian per square metre per nanometer (\(W/sr/m^2/nm\)) according to Rayleigh-Jeans law.

Parameters

temperature (float) – Temperature \(T[K]\) in kelvin degrees.
shape (colour.colorimetry.spectrum.SpectralShape) – Spectral shape used to create the spectral distribution of the planckian radiator.

Returns

Blackbody spectral distribution with values in watts per steradian per square metre per nanometer (\(W/sr/m^2/nm\)).

Return type

colour.SpectralDistribution

Notes

The Rayleigh-Jeans law agrees with experimental results at large wavelengths (low frequencies) but strongly disagrees at short wavelengths (high frequencies). This inconsistency between observations and the predictions of classical physics is commonly known as the ultraviolet catastrophe.

Examples

>>> from colour.utilities import numpy_print_options
>>> with numpy_print_options(suppress=True):
...     sd_rayleigh_jeans(5000, shape=SpectralShape(400, 700, 20))
...     
...
SpectralDistribution([[     400.        ,  1616829.9106941...],
                      [     420.        ,  1330169.9688456...],
                      [     440.        ,  1104316.5840408...],
                      [     460.        ,   924427.7490112...],
                      [     480.        ,   779721.2146480...],
                      [     500.        ,   662253.5314203...],
                      [     520.        ,   566097.0941823...],
                      [     540.        ,   486776.1157138...],
                      [     560.        ,   420874.0917050...],
                      [     580.        ,   365756.7299433...],
                      [     600.        ,   319373.8095198...],
                      [     620.        ,   280115.7588306...],
                      [     640.        ,   246708.6655722...],
                      [     660.        ,   218136.6091932...],
                      [     680.        ,   193583.6389284...],
                      [     700.        ,   172390.0279623...]],
                     SpragueInterpolator,
                     {},
                     Extrapolator,
                     {'method': 'Constant', 'left': None, 'right': None})