Exponential

class gammapy.astro.population.Exponential

Bases: Fittable1DModel

Exponential distribution.

\[f(z) = A \exp \left(- \frac{|z|}{z_0} \right)\]

Usually used for height distribution above the Galactic plane, with 0.05 kpc as a commonly used birth height distribution.

Parameters:

amplitudefloat

See model formula.

z_0float

Scale height of the distribution.

See also

CaseBattacharya1998, Paczynski1990, YusifovKucuk2004, Lorimer2006

YusifovKucuk2004B, FaucherKaspi2006, Exponential

Attributes Summary

amplitude
evolved
param_names	Names of the parameters that describe models of this type.
z_0

Methods Summary

evaluate(z, amplitude, z_0)

Evaluate model.

Attributes Documentation

amplitude

evolved = False

param_names = ('amplitude', 'z_0')

Names of the parameters that describe models of this type.

The parameters in this tuple are in the same order they should be passed in when initializing a model of a specific type. Some types of models, such as polynomial models, have a different number of parameters depending on some other property of the model, such as the degree.

When defining a custom model class the value of this attribute is automatically set by the Parameter attributes defined in the class body.

z_0

Methods Documentation

static evaluate(z, amplitude, z_0)

Evaluate model.

__init__(amplitude=1, z_0=0.05, **kwargs)

classmethod __new__(*args, **kwargs)