Source code for astrophot.models.moffat_model

import torch
import numpy as np

from .galaxy_model_object import Galaxy_Model
from .psf_model_object import PSF_Model
from ._shared_methods import parametric_initialize, select_target
from ..utils.decorators import ignore_numpy_warnings, default_internal
from ..utils.parametric_profiles import moffat_np
from ..utils.conversions.functions import moffat_I0_to_flux, general_uncertainty_prop

__all__ = ["Moffat_Galaxy", "Moffat_PSF"]


def _x0_func(model_params, R, F):
    return 2.0, R[4], F[0]


def _wrap_moffat(R, n, rd, i0):
    return moffat_np(R, n, rd, 10 ** (i0))


[docs] class Moffat_Galaxy(Galaxy_Model): """basic galaxy model with a Moffat profile for the radial light profile. The functional form of the Moffat profile is defined as: I(R) = I0 / (1 + (R/Rd)^2)^n where I(R) is the brightness profile as a function of semi-major axis, R is the semi-major axis length, I0 is the central flux density, Rd is the scale length for the profile, and n is the concentration index which controls the shape of the profile. Parameters: n: Concentration index which controls the shape of the brightness profile I0: brightness at the center of the profile, represented as the log of the brightness divided by pixel scale squared. Rd: scale length radius """ model_type = f"moffat {Galaxy_Model.model_type}" parameter_specs = { "n": {"units": "none", "limits": (0.1, 10), "uncertainty": 0.05}, "Rd": {"units": "arcsec", "limits": (0, None)}, "I0": {"units": "log10(flux/arcsec^2)"}, } _parameter_order = Galaxy_Model._parameter_order + ("n", "Rd", "I0") useable = True
[docs] @torch.no_grad() @ignore_numpy_warnings @select_target @default_internal def initialize(self, target=None, parameters=None, **kwargs): super().initialize(target=target, parameters=parameters) parametric_initialize( self, parameters, target, _wrap_moffat, ("n", "Rd", "I0"), _x0_func )
[docs] @default_internal def total_flux(self, parameters=None): return moffat_I0_to_flux( 10 ** parameters["I0"].value, parameters["n"].value, parameters["Rd"].value, parameters["q"].value, )
[docs] @default_internal def total_flux_uncertainty(self, parameters=None): return general_uncertainty_prop( (10 ** parameters["I0"].value, parameters["n"].value, parameters["Rd"].value, parameters["q"].value ), ((10 ** parameters["I0"].value) * parameters["I0"].uncertainty * torch.log(10*torch.ones_like(parameters["I0"].value)), parameters["n"].uncertainty, parameters["Rd"].uncertainty, parameters["q"].uncertainty ), moffat_I0_to_flux )
from ._shared_methods import moffat_radial_model as radial_model
[docs] class Moffat_PSF(PSF_Model): """basic point source model with a Moffat profile for the radial light profile. The functional form of the Moffat profile is defined as: I(R) = I0 / (1 + (R/Rd)^2)^n where I(R) is the brightness profile as a function of semi-major axis, R is the semi-major axis length, I0 is the central flux density, Rd is the scale length for the profile, and n is the concentration index which controls the shape of the profile. Parameters: n: Concentration index which controls the shape of the brightness profile I0: brightness at the center of the profile, represented as the log of the brightness divided by pixel scale squared. Rd: scale length radius """ model_type = f"moffat {PSF_Model.model_type}" parameter_specs = { "n": {"units": "none", "limits": (0.1, 10), "uncertainty": 0.05}, "Rd": {"units": "arcsec", "limits": (0, None)}, "I0": {"units": "log10(flux/arcsec^2)", "value": 0., "locked": True}, } _parameter_order = PSF_Model._parameter_order + ("n", "Rd", "I0") useable = True model_integrated = False
[docs] @torch.no_grad() @ignore_numpy_warnings @select_target @default_internal def initialize(self, target=None, parameters=None, **kwargs): super().initialize(target=target, parameters=parameters) parametric_initialize( self, parameters, target, _wrap_moffat, ("n", "Rd", "I0"), _x0_func )
from ._shared_methods import moffat_radial_model as radial_model
[docs] @default_internal def total_flux(self, parameters=None): return moffat_I0_to_flux( 10 ** parameters["I0"].value, parameters["n"].value, parameters["Rd"].value, torch.ones_like(parameters["n"].value), )
[docs] @default_internal def total_flux_uncertainty(self, parameters=None): return general_uncertainty_prop( (10 ** parameters["I0"].value, parameters["n"].value, parameters["Rd"].value, torch.ones_like(parameters["n"].value) ), ((10 ** parameters["I0"].value) * parameters["I0"].uncertainty * torch.log(10*torch.ones_like(parameters["I0"].value)), parameters["n"].uncertainty, parameters["Rd"].uncertainty, torch.zeros_like(parameters["n"].value) ), moffat_I0_to_flux )
from ._shared_methods import radial_evaluate_model as evaluate_model