Source code for dust_extinction.conversions
from astropy.modeling import Fittable1DModel, Parameter
__all__ = ["AxAvToExv"]
[docs]
class AxAvToExv(Fittable1DModel):
"""
Model to convert from A(x)/A(V) to E(x-V)
Parameters
----------
Av : float
dust column in A(V) [mag]
"""
Av = Parameter(description="A(V)", default=1.0, min=0.0)
[docs]
@staticmethod
def evaluate(axav, Av):
"""
AlAvToElv function
Parameters
----------
axav : np array (float)
E(x-V)/E(B-V) values
Returns
-------
exv : np array (float)
E(x - V)
"""
return (axav - 1.0) * Av
# Removed 4 Sep 2019 as this code is never used due to this model
# only is ever used in a compound model, hence the analytic derivatives
# are never used. Code never used or tested, better to not have it.
# The code is kept as a comment if in the future there is a need for it.
#
# @staticmethod
# def fit_deriv(axav, Av):
# """
# Derivatives of the AxAvtoElv function with respect to the parameters
# """
# # derivatives
# d_Av = axav - 1.0
#
# return [d_Av]