from typing import Optional
import numpy as np
from ..param import forward
from .base import Model
from . import func
from ..image import TargetImage, ModelImage, PSFImage
from ..utils.initialize import recursive_center_of_mass
from ..utils.decorators import ignore_numpy_warnings, combine_docstrings
from .. import config
from ..backend_obj import backend, ArrayLike
from ..errors import InvalidTarget
from .mixins import SampleMixin, GradMixin
__all__ = ("ComponentModel",)
[docs]
@combine_docstrings
class ComponentModel(GradMixin, SampleMixin, Model):
"""Component of a model for an object in an image.
This is a single component of an image model. It has a position on the sky
determined by `center` and may or may not be convolved with a PSF to represent some data.
**Parameters:**
- `center`: The center of the component in arcseconds [x, y] defined on the tangent plane.
**Options:**
- `psf_convolve`: Whether to convolve the model with a PSF. (bool)
"""
_parameter_specs = {"center": {"units": "arcsec", "shape": (2,), "dynamic": True}}
usable = False
psf_convolve = True
internal_psf = False
_options = ("psf_convolve",)
def __init__(self, *args, psf=None, **kwargs):
super().__init__(*args, **kwargs)
self.psf = psf
self.saveattrs.add("window.extent")
@property
def target(self):
return self._target
@target.setter
def target(self, tar):
if tar is None:
self._target = None
return
elif not isinstance(tar, TargetImage):
raise InvalidTarget(
f"AstroPhot {self.__class__.__name__} target must be a TargetImage instance."
)
try:
del self._target # Remove old target if it exists
except AttributeError:
pass
self._target = tar
@property
def psf(self):
if self._psf is None:
return self.target.psf
return self._psf
@psf.setter
def psf(self, psf):
try:
del self._psf # Remove old psf if it exists
except AttributeError:
pass
if psf is None:
self._psf = None
elif isinstance(psf, PSFImage):
self._psf = psf
elif isinstance(psf, Model):
self._psf = psf
else:
self._psf = PSFImage(data=psf)
config.logger.warning(
f"PSF provided to {self.__class__.__name__} was not a PSFImage or Model instance, so it was converted to a PSFImage assuming no upsampling."
)
def _prep_psf(self):
if not self.psf_convolve:
return None, 1, 0
psf = self.psf
if isinstance(psf, PSFImage):
return psf._data, psf.upsample, psf.pad
if isinstance(psf, Model):
return psf, psf.upsample, psf.pad
return None, 1, 0
# Initialization functions
######################################################################
[docs]
@ignore_numpy_warnings
def initialize(self):
"""Determine initial values for the center coordinates. This is done
with a local center of mass search which iterates by finding
the center of light in a window, then iteratively updates
until the iterations move by less than a pixel.
"""
if self.psf is not None and isinstance(self.psf, Model):
self.psf.initialize()
# Use center of window if a center hasn't been set yet
if self.center.initialized:
return
target_area = self.target[self.window]
dat = np.copy(backend.to_numpy(target_area._data))
mask = backend.to_numpy(target_area._mask)
dat[mask] = np.nanmedian(dat[~mask])
COM = recursive_center_of_mass(dat)
if not np.all(np.isfinite(COM)):
return
COM_center = target_area.pixel_to_plane(
*backend.as_array(COM, dtype=config.DTYPE, device=config.DEVICE), ()
)
self.center.value = COM_center
[docs]
@forward
def pixel_brightness(self, i, j, _CD=None, _crtan=None, _crpix=None):
"""Evaluate the model at the pixel coordinates defined by i and j (of the target image)."""
if _CD is None:
x, y = self.target.pixel_to_plane(i, j)
else:
x, y = self.target.pixel_to_plane(i, j, CD=_CD, crtan=_crtan, _crpix=_crpix)
return self.brightness(x, y)
[docs]
@forward
def sample(
self,
I_: ArrayLike,
J_: ArrayLike,
psf: ArrayLike = None,
crop: int = 0,
downsample: int = 1,
_CD: Optional[ArrayLike] = None,
_crtan: Optional[ArrayLike] = None,
_crpix: Optional[ArrayLike] = None,
):
Z = self.pixel_brightness(I_, J_, _CD=_CD, _crtan=_crtan, _crpix=_crpix)
Z = self._pixel_integrator(Z)
I_, J_ = self._pixel_center_finder(I_, J_)
Z = self._adaptive_integrator(
Z,
I_,
J_,
downsample,
lambda i, j: self.pixel_brightness(i, j, _CD=_CD, _crtan=_crtan, _crpix=_crpix),
)
if _CD is None:
Z = Z * self.target.pixel_collecting_area(I_, J_, downsample)
else:
Z = Z * self.target.pixel_collecting_area(I_, J_, downsample, CD=_CD)
if psf is not None:
if isinstance(psf, Model):
psf = psf()._data
if psf.shape != (1, 1): # skip if identity PSF
Z = func.convolve(Z, psf)
Z = Z[crop : Z.shape[0] - crop, crop : Z.shape[1] - crop]
Z = func.downsample(Z, downsample)
return Z
@forward
def __call__(
self,
_CD: Optional[ArrayLike] = None,
_crtan: Optional[ArrayLike] = None,
_crpix: Optional[ArrayLike] = None,
_psf: Optional[ArrayLike] = None,
) -> ModelImage:
psf, upsample, pad = self._prep_psf()
if _psf is not None and not isinstance(psf, Model) and self.psf_convolve:
psf = _psf
working_image = self.target.model_image(self.window)
I, J = self._pixel_meshgridder(self.target, self.window, pad, upsample)
# pixel_collecting_area: Units from flux/arcsec^2 to flux, multiply by pixel area
working_image._data = self.sample(
I,
J,
psf=psf,
crop=pad,
downsample=upsample,
_CD=_CD,
_crtan=_crtan,
_crpix=_crpix,
)
return working_image
