Sine1D

class astropy.modeling.functional_models.Sine1D

Bases: astropy.modeling.Fittable1DModel

One dimensional Sine model.

Parameters:

amplitude : float

Oscillation amplitude

frequency : float

Oscillation frequency

phase : float

Oscillation phase

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

Const1D, Linear1D

Notes

Model formula:

\[f(x) = A \sin(2 \pi f x + 2 \pi p)\]

Examples

import numpy as np
import matplotlib.pyplot as plt

from astropy.modeling.models import Sine1D

plt.figure()
s1 = Sine1D(amplitude=1, frequency=.25)
r=np.arange(0, 10, .01)

for amplitude in range(1,4):
     s1.amplitude = amplitude
     plt.plot(r, s1(r), color=str(0.25 * amplitude), lw=2)

plt.axis([0, 10, -5, 5])
plt.show()

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

Attributes Summary

amplitude
frequency
param_names
phase

Methods Summary

evaluate(x, amplitude, frequency, phase)	One dimensional Sine model function
fit_deriv(x, amplitude, frequency, phase)	One dimensional Sine model derivative

Attributes Documentation

amplitude

frequency

param_names = ('amplitude', 'frequency', 'phase')

phase

Methods Documentation

static evaluate(x, amplitude, frequency, phase)

One dimensional Sine model function

static fit_deriv(x, amplitude, frequency, phase)

One dimensional Sine model derivative