BaseField#

class lsst.images.fields.BaseField#

Bases: ABC

An abstract base class for parametric or interpolated 2-d functions, generally representing some sort of calculated image.

Notes

The field hierarchy is closed to the types in this package, so we can enumerate all of the serializations and avoid any kind of extension system. All field types are immutable.

Field types implement the function call operator and both multiplication and division by a constant via operator overloading. Subclasses provide those operations by implementing the _evaluate and _multiply_constant hooks (respectively).

This interface will probably change in the future to incorporate options for dealing with out-of-bounds positions. At present the behavior for such positions is implementation-specific and should not be relied upon.

Attributes Summary

`bounds`	The region over which this field can be evaluated (`Bounds`).
`is_constant`	Whether the field is spatially constant (`bool`).
`unit`	The units of the field (`astropy.units.UnitBase` or `None`).

Methods Summary

`__call__`([point, x, y, quantity])	Call self as a function.
`make_legacy_photo_calib`(image_unit)	Make a legacy `lsst.afw.image.PhotoCalib` for an image with the given units, if that is possible without a photometric scaling field.
`render`([bbox, dtype])	Create an image realization of the field.
`to_legacy`()	Convert to a legacy `lsst.afw.math.BoundedField`.
`to_legacy_photo_calib`(image_unit)	Convert to a legacy `lsst.afw.image.PhotoCalib`.

Attributes Documentation

bounds#: The region over which this field can be evaluated (Bounds).

is_constant#: Whether the field is spatially constant (bool).

unit#: The units of the field (astropy.units.UnitBase or None).

Methods Documentation

__call__(point=None, /, *, x=None, y=None, quantity=False)#

Call self as a function.

Parameters:

point (Union[XY[Any], YX[Any], None], default: None)
x (Any, default: None)
y (Any, default: None)
quantity (bool, default: False)

Return type:

float | ndarray | Quantity

static make_legacy_photo_calib(image_unit)#

Make a legacy lsst.afw.image.PhotoCalib for an image with the given units, if that is possible without a photometric scaling field.

Parameters:: image_unit (UnitBase) – Units of the image the photometric calibration applies to.
Return type:: TypeAliasType | None

abstract render(bbox=None, *, dtype=None)#

Create an image realization of the field.

Parameters:

bbox (Box | None, default: None) – Bounding box of the image. If not provided, self.bounds.bbox will be used.
dtype (TypeAliasType | None, default: None) – Pixel data type for the returned image.

Return type:

Image

to_legacy()#

Convert to a legacy lsst.afw.math.BoundedField.

Return type:: TypeAliasType

to_legacy_photo_calib(image_unit)#

Convert to a legacy lsst.afw.image.PhotoCalib.

Parameters:: image_unit (UnitBase) – The units of the pixels the returned PhotoCalib will be associated with.
Return type:: TypeAliasType