GaussianAbsorption1D

class astropy.modeling.functional_models.GaussianAbsorption1D

Bases: astropy.modeling.Fittable1DModel

One dimensional Gaussian absorption line model.

Parameters:

amplitude : float

Amplitude of the gaussian absorption.

mean : float

Mean of the gaussian.

stddev : float

Standard deviation of the gaussian.

Other Parameters:  

fixed : a dict

A dictionary {parameter_name: boolean} of parameters to not be varied during fitting. True means the parameter is held fixed. Alternatively the fixed property of a parameter may be used.

tied : dict

A dictionary {parameter_name: callable} of parameters which are linked to some other parameter. The dictionary values are callables providing the linking relationship. Alternatively the tied property of a parameter may be used.

bounds : dict

A dictionary {parameter_name: boolean} of lower and upper bounds of parameters. Keys are parameter names. Values are a list of length 2 giving the desired range for the parameter. Alternatively the min and max properties of a parameter may be used.

eqcons : list

A list of functions of length n such that eqcons[j](x0,*args) == 0.0 in a successfully optimized problem.

ineqcons : list

A list of functions of length n such that ieqcons[j](x0,*args) >= 0.0 is a successfully optimized problem.

See also

Gaussian1D

Notes

Model formula:

\[f(x) = 1 - A e^{- \frac{\left(x - x_{0}\right)^{2}}{2 \sigma^{2}}}\]

Examples

import numpy as np
import matplotlib.pyplot as plt
from astropy.modeling.models import GaussianAbsorption1D

plt.figure()
s1 = GaussianAbsorption1D()
r = np.arange(-5, 5, .01)
for factor in range(1, 4):
    s1.amplitude = factor
    plt.plot(r, s1(r), color=str(0.25 * factor), lw=2)

plt.axis([-5, 5, -3, 2])
plt.show()

(Source code, png, hires.png, pdf)

Attributes Summary

amplitude
mean
param_names
stddev

Methods Summary

evaluate(x, amplitude, mean, stddev)	GaussianAbsorption1D model function.
fit_deriv(x, amplitude, mean, stddev)	GaussianAbsorption1D model function derivatives.

Attributes Documentation

amplitude

mean

param_names = ('amplitude', 'mean', 'stddev')

stddev

Methods Documentation

static evaluate(x, amplitude, mean, stddev)

GaussianAbsorption1D model function.

static fit_deriv(x, amplitude, mean, stddev)

GaussianAbsorption1D model function derivatives.