LinearPhaseFunc

class sbpy.photometry.LinearPhaseFunc(H, S, **kwargs)[source]

Bases: sbpy.photometry.DiskIntegratedPhaseFunc

Linear phase function model

Examples

>>> # Define a linear phase function model with absolute magnitude
>>> # H = 5 and slope = 0.04 mag/deg = 2.29 mag/rad
>>> import astropy.units as u
>>> from sbpy.calib import solar_fluxd
>>> from sbpy.photometry import LinearPhaseFunc
>>>
>>> linear_phasefunc = LinearPhaseFunc(5 * u.mag, 0.04 * u.mag/u.deg,
...     radius = 300 * u.km, wfb = 'V')
>>> with solar_fluxd.set({'V': -26.77 * u.mag}):
...     pha = np.linspace(0, 180, 200) * u.deg
...     mag = linear_phasefunc.to_mag(pha)
...     ref = linear_phasefunc.to_ref(pha)
...     geomalb = linear_phasefunc.geomalb
...     phaseint = linear_phasefunc.phaseint
...     bondalb = linear_phasefunc.bondalb
>>> print('Geometric albedo is {0:.3}'.format(geomalb))
Geometric albedo is 0.0487
>>> print('Bond albedo is {0:.3}'.format(bondalb))
Bond albedo is 0.0179
>>> print('Phase integral is {0:.3}'.format(phaseint))
Phase integral is 0.367

Initialize DiskIntegratedPhaseFunc

Parameters
radiusastropy.units.Quantity, optional

Radius of object. Required if conversion between magnitude and reflectance is involved.

wfbQuantity, SpectralElement, string

Wavelengths, frequencies, or bandpasses. Bandpasses may be a filter name (string). Required if conversion between magnitude and reflectance is involved.

**kwargsoptional parameters accepted by

astropy.modeling.Model.__init__()

Attributes Summary

H

Absolute magnitude

S

Linear slope (mag/deg)

input_units

param_names

Methods Summary

evaluate(a, H, S)

Evaluate the model on some input variables.

fit_deriv(a, H, S)

Attributes Documentation

H

Absolute magnitude

S

Linear slope (mag/deg)

input_units = {'x': Unit("deg")}
param_names = ('H', 'S')

Methods Documentation

static evaluate(a, H, S)[source]

Evaluate the model on some input variables.

static fit_deriv(a, H, S)[source]