CellField

final class lsst.images.cells.CellField(bounds, array, unit=None)

Bases: BaseField

A piecewise 2-d function on a cell-coadd grid.

Parameters:

• bounds (CellGridBounds) – Description of the cell grid and any missing cells. Array entries for missing cells should be NaN.

• array (ndarray) – A 2-d array of cell values with shape bounds.subgrid_size.as_tuple().

• unit (UnitBase | None, default: None) – Units of the field values, or None if dimensionless.

Notes

CellField is not directly serializable and is not included in the Field union type alias as a result. A Mapping of CellField is instead serializable via CellApertureCorrectionMapSerializationModel.

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.
from_legacy_aperture_correction(legacy, bounds)	Convert from a legacy lsst.cell_coadds.StitchedApertureCorrection.
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.
quantity_in_cell(key)	Return the quantity (value with units) of the field in the cell with the given index.
render([bbox, dtype])	Create an image realization of the field.
to_legacy()	Convert to a legacy lsst.afw.math.BoundedField.
to_legacy_aperture_correction()	Convert to a legacy lsst.cell_coadds.StitchedApertureCorrection.
to_legacy_photo_calib(image_unit)	Convert to a legacy lsst.afw.image.PhotoCalib.
value_in_cell(key)	Return the value of the field in the cell with the given index.

Attributes Documentation

bounds

is_constant

unit

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 from_legacy_aperture_correction(legacy, bounds)

Convert from a legacy lsst.cell_coadds.StitchedApertureCorrection.

Parameters:

• legacy (TypeAliasType) – Legacy field to convert.

• bounds (CellGridBounds) – The grid and bounds of the returned field.

Return type:

CellField

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

quantity_in_cell(key)

Return the quantity (value with units) of the field in the cell with the given index.

Parameters:

key (CellIJ) – Index of the cell to evaluate.

Return type:

Quantity

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_aperture_correction()

Convert to a legacy lsst.cell_coadds.StitchedApertureCorrection.

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

value_in_cell(key)

Return the value of the field in the cell with the given index.

Parameters:

key (CellIJ) – Index of the cell to evaluate.

Return type:

float