Sine1D

class astropy.modeling.functional_models.Sine1D(amplitude=1, frequency=1, phase=0, **kwargs)

Bases: astropy.modeling.Fittable1DModel

One dimensional Sine model.

Parameters

amplitudefloat

Oscillation amplitude

frequencyfloat

Oscillation frequency

phasefloat

Oscillation phase

Other Parameters

fixeda dict, optional

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.

tieddict, optional

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.

boundsdict, optional

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

eqconslist, optional

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

ineqconslist, optional

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()

(png, svg, pdf)

Attributes Summary

amplitude
frequency
input_units	This property is used to indicate what units or sets of units the evaluate method expects, and returns a dictionary mapping inputs to units (or None if any units are accepted).
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 = Parameter('amplitude', value=1.0)

frequency = Parameter('frequency', value=1.0)

input_units

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

phase = Parameter('phase', value=0.0)

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