CellField#

final class lsst.images.cells.CellField(bounds: CellGridBounds, array: ndarray, unit: UnitBase | None = None)#

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

Parameters#

array: A 2-d array of cell values with shape bounds.subgrid_size.as_tuple().
bounds: Description of the cell grid and any missing cells. Array entries for missing cells should be NaN.

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__`(*, x, y[, quantity])	Call self as a function.
`evaluate`(*, x, y, quantity)	Evaluate at non-gridded points.
`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.
`multiply_constant`(factor)	Multiply by a constant, returning a new field of the same type.
`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

Methods Documentation

__call__(*, x: ndarray, y: ndarray, quantity: bool = False) → ndarray | Quantity#: Call self as a function.

evaluate(*, x: ndarray, y: ndarray, quantity: bool) → ndarray | Quantity#

Evaluate at non-gridded points.

x: X coordinates to evaluate at.
y: Y coordinates to evaluate at; must be broadcast-compatible with x.
quantity: If True, return an astropy.units.Quantity instead of a numpy.ndarray. If unit is None, the returned object will be a dimensionless Quantity.

static from_legacy_aperture_correction(legacy: LegacyStichedApertureCorrection, bounds: CellGridBounds) → CellField#

static make_legacy_photo_calib(image_unit: astropy.units.UnitBase) → LegacyPhotoCalib | None#: Make a legacy lsst.afw.image.PhotoCalib for an image with the given units, if that is possible without a photometric scaling field.

multiply_constant(factor: float | Quantity | UnitBase) → CellField#

Multiply by a constant, returning a new field of the same type.

factor: Factor to multiply by. When this has units, those should multiply self.unit or set the units of the returned field if self.unit is None.

quantity_in_cell(key: CellIJ) → Quantity#: Return the quantity (value with units) of the field in the cell with the given index.

Create an image realization of the field.

bbox: Bounding box of the image. If not provided, self.bounds.bbox will be used.
dtype: Pixel data type for the returned image.

to_legacy() → LegacyBoundedField#: Convert to a legacy lsst.afw.math.BoundedField.

to_legacy_aperture_correction() → LegacyStichedApertureCorrection#: Convert to a legacy lsst.cell_coadds.StitchedApertureCorrection.

to_legacy_photo_calib(image_unit: astropy.units.UnitBase) → LegacyPhotoCalib#

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

image_unit: The units of the pixels the returned PhotoCalib will be associated with.

value_in_cell(key: CellIJ) → float#: Return the value of the field in the cell with the given index.