FlatGradient¶
- class lsst.ip.isr.FlatGradient(**kwargs)¶
Bases:
IsrCalib
Flat gradient measurements.
- Parameters:
- log
logging.Logger
, optional Log to write messages to. If
None
a default logger will be used.- **kwargs
Additional parameters.
- log
Attributes Summary
Methods Summary
apply
(target)Method to apply the calibration to the target object.
calibInfoFromDict
(dictionary)Handle common keywords.
computeFullModel
(x, y, is_itl)Compute the full gradient model given x/y and itl booleans.
computeGradientModel
(x, y)Compute the gradient model values.
computeRadialSplineModel
(radius)Compute the radial spline model values from radii.
Compute the radial spline model values from x/y.
determineCalibClass
(metadata, message)Attempt to find calibration class in metadata.
fromDetector
(detector)Modify the calibration parameters to match the supplied detector.
fromDict
(dictionary)Construct a FlatGradient from a dictionary of properties.
fromTable
(tableList)Construct a calibration from a list of tables.
Retrieve metadata associated with this calibration.
readFits
(filename, **kwargs)Read calibration data from a FITS file.
readText
(filename, **kwargs)Read calibration representation from a yaml/ecsv file.
setMetadata
(metadata)Store a copy of the supplied metadata with this calibration.
setParameters
(*, radialSplineNodes, ...[, ...])Set the parameters for the gradient model.
toDict
()Return a dictionary containing the calibration properties.
toTable
()Construct a list of table(s) containing the FlatGradient data.
updateMetadata
([camera, detector, ...])Update metadata keywords with new values.
updateMetadataFromExposures
(exposures)Extract and unify metadata information.
validate
([other])Validate that this calibration is defined and can be used.
writeFits
(filename)Write calibration data to a FITS file.
writeText
(filename[, format])Write the calibration data to a text file.
Attributes Documentation
- metadata¶
- requiredAttributes¶
Methods Documentation
- apply(target)¶
Method to apply the calibration to the target object.
- calibInfoFromDict(dictionary)¶
Handle common keywords.
This isn’t an ideal solution, but until all calibrations expect to find everything in the metadata, they still need to search through dictionaries.
- Parameters:
- dictionary
dict
orlsst.daf.base.PropertyList
Source for the common keywords.
- dictionary
- Raises:
- RuntimeError
Raised if the dictionary does not match the expected OBSTYPE.
- computeFullModel(x, y, is_itl)¶
Compute the full gradient model given x/y and itl booleans.
This returns the full model that can be applied directly to data that was used in a fit.
- Parameters:
- x
np.ndarray
Array of focal plane x values (mm).
- y
np.ndarray
Array of focal plane y values (mm).
- is_itl
np.ndarray
Boolean array of whether each point is from an ITL detector.
- x
- Returns:
- model
np.ndarray
Model values at each position.
- model
- computeGradientModel(x, y)¶
Compute the gradient model values.
The gradient model is a plane constrained to be 1.0 at the
centroidX
,centroidY
values. The outer gradient model is the same, except only applies at large radius (above theouterGradientRadius
). Dividing by this model will remove the planar gradient in a flat field. Note that the planar gradient pivot is always at the same position, and does not move with the radial gradient centroid so as to keep the model fit more stable.- Parameters:
- x
np.ndarray
Array of focal plane x values (mm).
- y
np.ndarray
Array of focal plane y values (mm).
- x
- Returns:
- gradientModel
np.ndarray
Gradient model values at the x/y positions.
- gradientModel
- computeRadialSplineModel(radius)¶
Compute the radial spline model values from radii.
The spline model is a 1D Akima spline. When computed, the values from the model describe the radial function of the full focal plane flat-field. Dividing by this model will yield a radially flattened flat-field.
- Parameters:
- radius
np.ndarray
Array of focal plane radii (mm).
- radius
- Returns:
- splineModel
np.ndarray
Spline model values at the radius positions.
- splineModel
- computeRadialSplineModelXY(x, y)¶
Compute the radial spline model values from x/y.
The spline model is a 1D Akima spline. When computed, the values from the model describe the radial function of the full focal plane flat-field. Dividing by this model will yield a radially flattened flat-field.
- Parameters:
- x
np.ndarray
Array of focal plane x values (mm).
- y
np.ndarray
Array of focal plane y values (mm).
- x
- Returns:
- splineModel
np.ndarray
Spline model values at the x/y positions.
- splineModel
- classmethod determineCalibClass(metadata, message)¶
Attempt to find calibration class in metadata.
- Parameters:
- Returns:
- calibClass
object
The class to use to read the file contents. Should be an
lsst.ip.isr.IsrCalib
subclass.
- calibClass
- Raises:
- ValueError
Raised if the resulting calibClass is the base
lsst.ip.isr.IsrClass
(which does not implement the content methods).
- fromDetector(detector)¶
Modify the calibration parameters to match the supplied detector.
- Parameters:
- detector
lsst.afw.cameraGeom.Detector
Detector to use to set parameters from.
- detector
- Raises:
- NotImplementedError
Raised if not implemented by a subclass. This needs to be implemented by subclasses for each calibration type.
- classmethod fromDict(dictionary)¶
Construct a FlatGradient from a dictionary of properties.
- Parameters:
- dictionary
dict
Dictionary of properties.
- dictionary
- Returns:
- calib
lsst.ip.isr.FlatGradient
Constructed calibration.
- calib
- classmethod fromTable(tableList)¶
Construct a calibration from a list of tables.
- Parameters:
- tableList
list
[astropy.table.Table
] List of table(s) to use to construct the FlatGradient.
- tableList
- Returns:
- calib
lsst.ip.isr.FlatGradient
The calibration defined in the table(s).
- calib
- getMetadata()¶
Retrieve metadata associated with this calibration.
- Returns:
- meta
lsst.daf.base.PropertyList
Metadata. The returned
PropertyList
can be modified by the caller and the changes will be written to external files.
- meta
- classmethod readFits(filename, **kwargs)¶
Read calibration data from a FITS file.
- Parameters:
- Returns:
- calib
lsst.ip.isr.IsrCalib
Calibration contained within the file.
- calib
- classmethod readText(filename, **kwargs)¶
Read calibration representation from a yaml/ecsv file.
- Parameters:
- Returns:
- calib
IsrCalibType
Calibration class.
- calib
- Raises:
- RuntimeError
Raised if the filename does not end in “.ecsv” or “.yaml”.
- setMetadata(metadata)¶
Store a copy of the supplied metadata with this calibration.
- Parameters:
- metadata
lsst.daf.base.PropertyList
Metadata to associate with the calibration. Will be copied and overwrite existing metadata.
- metadata
- setParameters(*, radialSplineNodes, radialSplineValues, itlRatio=1.0, centroidX=0.0, centroidY=0.0, centroidDeltaX=0.0, centroidDeltaY=0.0, gradientX=0.0, gradientY=0.0, outerGradientX=0.0, outerGradientY=0.0, outerGradientRadius=inf, normalizationFactor=1.0)¶
Set the parameters for the gradient model.
- Parameters:
- radialSplineNodes
np.ndarray
Array of spline nodes.
- radialSplineValues
np.ndarray
Array of spline values (same length as
radialSplineNodes
).- itlRatio
float
, optional Ratio of flat for ITL detectors to E2V detectors.
- centroidX
float
, optional X centroid of the focal plane (mm). This will be used as the pivot for the gradient plane.
- centroidY
float
, optional Y centroid of the focal plane (mm). This will be used as the pivot for the gradient plane.
- centroidDeltaX
float
, optional Centroid offset (mm). This is used in the radial function to allow for mis-centering in the illumination gradient.
- centroidDeltaY
float
, optional Centroid offset (mm). This is used in the radial function to allow for mis-centering in the illumination gradient.
- gradientX
float
, optional Slope of gradient in x direction (throughput/mm).
- gradientY
float
, optional Slope of gradient in y direction (throughput/mm).
- outerGradientX
float
, optional Slope of additional gradient in x direction (throughput/mm) that is only applied at focal plane radius greater than
outerGradientRadius
.- outerGradientY
float
, optional Slope of additional gradient in y direction (throughput/mm) that is only applied at focal plane radius greater than
outerGradientRadius
.- outerGradientRadius
float
, optional Minimum radius (mm) where the outer gradient is used.
- normalizationFactor
float
, optional Overall normalization factor (used to, e.g. make the center of the focal plane equal to 1.0 vs. a focal-plane average.
- radialSplineNodes
- toDict()¶
Return a dictionary containing the calibration properties.
- Returns:
- dictionary
dict
Dictionary of properties.
- dictionary
- toTable()¶
Construct a list of table(s) containing the FlatGradient data.
- Returns:
- tableList
list
[astropy.table.Table
] List of tables containing the FlatGradient information.
- tableList
- updateMetadata(camera=None, detector=None, filterName=None, setCalibId=False, setCalibInfo=False, setDate=False, **kwargs)¶
Update metadata keywords with new values.
- Parameters:
- camera
lsst.afw.cameraGeom.Camera
, optional Reference camera to use to set
_instrument
field.- detector
lsst.afw.cameraGeom.Detector
, optional Reference detector to use to set
_detector*
fields.- filterName
str
, optional Filter name to assign to this calibration.
- setCalibId
bool
, optional Construct the
_calibId
field from other fields.- setCalibInfo
bool
, optional Set calibration parameters from metadata.
- setDate
bool
, optional Ensure the metadata
CALIBDATE
fields are set to the current datetime.- kwargs
dict
orcollections.abc.Mapping
, optional Set of
key=value
pairs to assign to the metadata.
- camera
- updateMetadataFromExposures(exposures)¶
Extract and unify metadata information.
- Parameters:
- exposures
list
Exposures or other calibrations to scan.
- exposures
- validate(other=None)¶
Validate that this calibration is defined and can be used.
- writeFits(filename)¶
Write calibration data to a FITS file.
- writeText(filename, format='auto')¶
Write the calibration data to a text file.
- Parameters:
- Returns:
- used
str
The name of the file used to write the data. This may differ from the input if the format is explicitly chosen.
- used
- Raises:
- RuntimeError
Raised if filename does not end in a known extension, or if all information cannot be written.
Notes
The file is written to YAML/ECSV format and will include any associated metadata.