PhotodiodeCorrection

class lsst.ip.isr.PhotodiodeCorrection(table=None, **kwargs)

Bases: lsst.ip.isr.IsrCalib

Parameter set for photodiode correction.

These parameters are included in cameraGeom.Amplifier, but should be accessible externally to allow for testing.

Parameters:

table : numpy.array, optional

Lookup table; a 2-dimensional array of floats:

• one row for each row index (value of coef[0] in the amplifier)
• one column for each image value.

To avoid copying the table the last index should vary fastest (numpy default “C” order)

log : logging.Logger, optional

Logger to handle messages.

kwargs : dict, optional

Other keyword arguments to pass to the parent init.

Raises:

RuntimeError

Raised if the supplied table is not 2D, or if the table has fewer columns than rows (indicating that the indices are swapped).

Notes

The photodiode correction attributes stored are: abscissaCorrections : dict : [str, float] Correction value indexed by exposure pair

Attributes Summary

requiredAttributes

Methods Summary

apply(target)	Method to apply the calibration to the target object.
calibInfoFromDict(dictionary)	Handle common keywords.
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 PhotodiodeCorrection from a dictionary of properties.
fromTable(tableList)	Construct calibration from a list of tables.
getMetadata()	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.
toDict()	Return a dictionary containing the photodiode correction properties.
toTable()	Construct a list of tables containing the information in this calibration.
updateMetadata([setDate])	Update metadata keywords with new values.
validate()	Validate photodiode correction
writeFits(filename)	Write calibration data to a FITS file.
writeText(filename[, format])	Write the calibration data to a text file.

Attributes Documentation

requiredAttributes

Methods Documentation

apply(target)

Method to apply the calibration to the target object.

Parameters:

target : object

Thing to validate against.

Returns:

valid : bool

Returns true if the calibration was applied correctly.

Raises:

NotImplementedError

Raised if not implemented.

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 or lsst.daf.base.PropertyList

Source for the common keywords.

Raises:

RuntimeError

Raised if the dictionary does not match the expected OBSTYPE.

classmethod determineCalibClass(metadata, message)

Attempt to find calibration class in metadata.

Parameters:

metadata : dict or lsst.daf.base.PropertyList

Metadata possibly containing a calibration class entry.

message : str

Message to include in any errors.

Returns:

calibClass : object

The class to use to read the file contents. Should be an lsst.ip.isr.IsrCalib subclass.

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.

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 PhotodiodeCorrection from a dictionary of properties.

Parameters:

dictionary : dict

Dictionary of properties.

Returns:

calib : lsst.ip.isr.PhotodiodeCorrection

Constructed photodiode data.

Raises:

RuntimeError

Raised if the supplied dictionary is for a different calibration type.

classmethod fromTable(tableList)

Construct calibration from a list of tables.

This method uses the fromDict method to create the calibration after constructing an appropriate dictionary from the input tables.

Parameters:

tableList : list [astropy.table.Table]

List of tables to use to construct the crosstalk calibration.

Returns:

calib : lsst.ip.isr.PhotodiodeCorrection

The calibration defined in the tables.

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.

classmethod readFits(filename, **kwargs)

Read calibration data from a FITS file.

Parameters:

filename : str

Filename to read data from.

kwargs : dict or collections.abc.Mapping`, optional

Set of key=value pairs to pass to the fromTable method.

Returns:

calib : lsst.ip.isr.IsrCalib

Calibration contained within the file.

classmethod readText(filename, **kwargs)

Read calibration representation from a yaml/ecsv file.

Parameters:

filename : str

Name of the file containing the calibration definition.

kwargs : dict or collections.abc.Mapping`, optional

Set of key=value pairs to pass to the fromDict or fromTable methods.

Returns:

calib : IsrCalibType

Calibration class.

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.

toDict()

Return a dictionary containing the photodiode correction properties.

The dictionary should be able to be round-tripped through. fromDict.

Returns:

dictionary : dict

Dictionary of properties.

toTable()

Construct a list of tables containing the information in this calibration.

The list of tables should create an identical calibration after being passed to this class’s fromTable method.

Returns:

tableList : list [astropy.table.Table]

List of tables containing the photodiode correction information.

updateMetadata(setDate=False, **kwargs)

Update metadata keywords with new values.

This calls the base class’s method after ensuring the required calibration keywords will be saved.

Parameters:

setDate : bool, optional

Update the CALIBDATE fields in the metadata to the current time. Defaults to False.

kwargs

Other keyword parameters to set in the metadata.

validate()

Validate photodiode correction

writeFits(filename)

Write calibration data to a FITS file.

Parameters:

filename : str

Filename to write data to.

Returns:

used : str

The name of the file used to write the data.

writeText(filename, format='auto')

Write the calibration data to a text file.

Parameters:

filename : str

Name of the file to write.

format : str

Format to write the file as. Supported values are:

"auto" : Determine filetype from filename. "yaml" : Write as yaml. "ecsv" : Write as ecsv.

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.

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.