HG

class sbpy.photometry.HG(*args, **kwargs)[source]

Bases: DiskIntegratedPhaseFunc

HG photometric phase model (Bowell et al. 1989)

Examples

>>> # Define the phase function for Ceres with H = 3.34, G = 0.12
>>> import astropy.units as u
>>> from sbpy.calib import solar_fluxd
>>> from sbpy.photometry import HG
>>> ceres = HG(3.34 * u.mag, 0.12, radius = 480 * u.km, wfb = 'V')
>>> with solar_fluxd.set({'V': -26.77 * u.mag}):
...     print('geometric albedo = {0:.4f}'.format(ceres.geomalb))
...     print('phase integral = {0:.4f}'.format(ceres.phaseint))
geometric albedo = 0.0878
phase integral = 0.3644

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

G

H

param_names

Names of the parameters that describe models of this type.

Methods Summary

evaluate(pha, hh, gg)

Evaluate the model on some input variables.

fit_deriv(pha, hh, gg)

Attributes Documentation

G = Parameter('G', value=0.4, bounds=[-0.253, 1.194])
H = Parameter('H', value=8.0)
param_names = ('H', 'G')

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.

Methods Documentation

static evaluate(pha, hh, gg)[source]

Evaluate the model on some input variables.

static fit_deriv(pha, hh, gg)[source]