import torch
from ...param import forward
from ...backend_obj import ArrayLike
from ...utils.decorators import ignore_numpy_warnings
from ...utils.parametric_profiles import ferrer_np
from .._shared_methods import parametric_initialize, parametric_segment_initialize
from .. import func
[docs]
def x0_func(model_params, R, F):
return R[5], 1, 1, 10 ** F[0]
[docs]
class FerrerMixin:
"""Modified Ferrer radial light profile (Binney & Tremaine 1987).
This model has a relatively flat brightness core and then a truncation. It
is used in specialized circumstances such as fitting the bar of a galaxy.
The functional form of the Modified Ferrer profile is defined as:
.. math::
I(R) = I_0 \\left(1 - \\left(\\frac{R}{r_{\\rm out}}\\right)^{2-\\beta}\\right)^{\\alpha}
where ``rout`` is the outer truncation radius, ``alpha`` controls the steepness
of the truncation, ``beta`` controls the shape, and ``I0`` is the intensity at
the center of the profile.
:param rout: Outer truncation radius in arcseconds.
:param alpha: Inner slope parameter.
:param beta: Outer slope parameter.
:param I0: Intensity at the center of the profile in flux/arcsec^2
"""
_model_type = "ferrer"
_parameter_specs = {
"rout": {
"units": "arcsec",
"valid": (0.0, None),
"shape": (),
"dynamic": True,
"description": "Outer truncation radius in arcseconds.",
},
"alpha": {
"units": "unitless",
"valid": (0, 10),
"shape": (),
"dynamic": True,
"description": "Inner slope parameter.",
},
"beta": {
"units": "unitless",
"valid": (0, 2),
"shape": (),
"dynamic": True,
"description": "Outer slope parameter.",
},
"I0": {
"units": "flux/arcsec^2",
"valid": (0, None),
"shape": (),
"dynamic": True,
"description": "Intensity at the center of the profile in flux/arcsec^2",
},
}
[docs]
@torch.no_grad()
@ignore_numpy_warnings
def initialize(self):
super().initialize()
parametric_initialize(
self,
self.target[self.window],
ferrer_np,
("rout", "alpha", "beta", "I0"),
x0_func,
)
[docs]
@forward
def radial_model(
self, R: ArrayLike, rout: ArrayLike, alpha: ArrayLike, beta: ArrayLike, I0: ArrayLike
) -> ArrayLike:
return func.ferrer(R, rout, alpha, beta, I0)
[docs]
class iFerrerMixin:
"""Modified Ferrer radial light profile (Binney & Tremaine 1987).
This model has a relatively flat brightness core and then a truncation. It
is used in specialized circumstances such as fitting the bar of a galaxy.
The functional form of the Modified Ferrer profile is defined as:
.. math::
I(R) = I_0 \\left(1 - \\left(\\frac{R}{r_{\\rm out}}\\right)^{2-\\beta}\\right)^{\\alpha}
where ``rout`` is the outer truncation radius, ``alpha`` controls the steepness
of the truncation, ``beta`` controls the shape, and ``I0`` is the intensity at
the center of the profile.
``rout``, ``alpha``, ``beta``, and ``I0`` are batched by their first dimension,
allowing for multiple Ferrer profiles to be defined at once.
:param rout: Outer truncation radius in arcseconds.
:param alpha: Inner slope parameter.
:param beta: Outer slope parameter.
:param I0: Intensity at the center of the profile in flux/arcsec^2
"""
_model_type = "ferrer"
_parameter_specs = {
"rout": {
"units": "arcsec",
"valid": (0.0, None),
"shape": (None,),
"dynamic": True,
"description": "Outer truncation radius in arcseconds.",
},
"alpha": {
"units": "unitless",
"valid": (0, 10),
"shape": (None,),
"dynamic": True,
"description": "Inner slope parameter.",
},
"beta": {
"units": "unitless",
"valid": (0, 2),
"shape": (None,),
"dynamic": True,
"description": "Outer slope parameter.",
},
"I0": {
"units": "flux/arcsec^2",
"valid": (0.0, None),
"shape": (None,),
"dynamic": True,
"description": "Intensity at the center of the profile in flux/arcsec^2",
},
}
[docs]
@torch.no_grad()
@ignore_numpy_warnings
def initialize(self):
super().initialize()
parametric_segment_initialize(
model=self,
target=self.target[self.window],
prof_func=ferrer_np,
params=("rout", "alpha", "beta", "I0"),
x0_func=x0_func,
segments=self.segments,
)
[docs]
@forward
def iradial_model(
self,
i: int,
R: ArrayLike,
rout: ArrayLike,
alpha: ArrayLike,
beta: ArrayLike,
I0: ArrayLike,
) -> ArrayLike:
return func.ferrer(R, rout[i], alpha[i], beta[i], I0[i])
[docs]
class FerrerPSFMixin:
"""Modified Ferrer radial light profile (Binney & Tremaine 1987).
This model has a relatively flat brightness core and then a truncation. It
is used in specialized circumstances such as fitting the bar of a galaxy.
The functional form of the Modified Ferrer profile is defined as:
.. math::
I(R) = I_0 \\left(1 - \\left(\\frac{R}{r_{\\rm out}}\\right)^{2-\\beta}\\right)^{\\alpha}
where ``rout`` is the outer truncation radius, ``alpha`` controls the steepness
of the truncation, ``beta`` controls the shape, and ``I0`` is the intensity at
the center of the profile.
:param rout: Outer truncation radius in pixels.
:param alpha: Inner slope parameter.
:param beta: Outer slope parameter.
:param I0: Intensity at the center of the profile in flux/pix^2
"""
_model_type = "ferrer"
_parameter_specs = {
"rout": {
"units": "pix",
"valid": (0.0, None),
"shape": (),
"dynamic": True,
"description": "Outer truncation radius in pixels.",
},
"alpha": {
"units": "unitless",
"valid": (0, 10),
"shape": (),
"dynamic": True,
"description": "Inner slope parameter.",
},
"beta": {
"units": "unitless",
"valid": (0, 2),
"shape": (),
"dynamic": True,
"description": "Outer slope parameter.",
},
"I0": {
"units": "flux/pix^2",
"valid": (0, None),
"shape": (),
"dynamic": False,
"value": 1.0,
"description": "Intensity at the center of the profile in flux/pix^2",
},
}
[docs]
@torch.no_grad()
@ignore_numpy_warnings
def initialize(self):
super().initialize()
parametric_initialize(
self,
self.target[self.window],
ferrer_np,
("rout", "alpha", "beta", "I0"),
x0_func,
)
[docs]
@forward
def radial_model(
self, R: ArrayLike, rout: ArrayLike, alpha: ArrayLike, beta: ArrayLike, I0: ArrayLike
) -> ArrayLike:
return func.ferrer(R, rout, alpha, beta, I0)
