ArrayPSF#

class scarlet2.ArrayPSF(morphology: Array)[source]#

Bases: PSF

PSF defined by an image array

Warning

The number of pixels in morphology should be odd, and the centroid of the PSF image should be in the central pixel. If that is not the case, one creates an effective shift by the PSF, which is not captured by the coordinate convention of the frame, e.g. its wcs.

See #96 from more details.

__call__()[source]#

Evaluate PSF

Returns:

2D image, normalized to total flux=1

Return type:

array

get(name=None)#

Get parameter(s) from this module

Parameters:

name (str, optional) – Name of parameter. If not set, returns all parameters.

Returns:

requested data arrays for parameters

Return type:

dict

morphology: Array#

The PSF morphology image. Can be 2D (height, width) or 3D (channel, height, width)

property parameters#

Parameters defined for this module

Returns:

name: (node, param) mapping for all parameters

Return type:

dict

replace(name, value)#

Replace member attribuge name with value

Parameters:
  • name (str) – Name of member to replace

  • value (any) – Value to replace member with

Returns:

The modified module.

Return type:

Module

replace_subtree(where, value, parameters=None)#

Replace the subtree where(self) with value and carry over all other parameters

Unlike replace(), value does not need to have the same structure as the subtree it replaces, e.g. an array morphology can be replaced by a SersicMorphology. Parameters defined for this module remain attached to the same nodes, except those inside the replaced subtree, which are dropped.

Parameters:
  • where (callable) – Function module -> node that selects the subtree to replace, as in equinox.tree_at()

  • value (any) – Replacement for the subtree. If this module has a frame, attributes of value given in sky coordinates are converted to pixel coordinates of that frame.

  • parameters (callable, optional) – Function module -> None that is called with the new module inside of a Parameters context to define parameters for the replacement, e.g. by calling Parameter on nodes of value.

Returns:

The modified module.

Return type:

Module

Examples

>>> sersic = SersicMorphology(n=jnp.array(2.), size=jnp.array(2.), shape=morph.shape)
>>> def sersic_parameters(morph):
>>>     Parameter(morph.n, name="n:0", prior=dist.Uniform(0.5, 6))
>>>     Parameter(morph.size, name="size:0", constraint=constraints.positive, stepsize=0.1)
>>>
>>> scene_ = scene.replace_subtree(lambda sc: sc.sources[0].morphology, sersic, sersic_parameters)

See also

remap()

set(values)#

Set parameter(s) from this module with values

Parameters:

values (dict[str,jnp.array]) – values to replace parameters with, identified by their name

Returns:

new module with parameter(s) replaced by values

Return type:

Module

property shape#

Shape of the PSF model