SkyMatchStep

class jwst.skymatch.SkyMatchStep(*args, **kwargs)

Bases: JwstStep

SkyMatchStep: Subtraction or equalization of sky background in science images.

Create a Step instance.

Parameters:

• name (str, optional) – The name of the Step instance. Used in logging messages and in cache filenames. If not provided, one will be generated based on the class name.

• parent (Step instance, optional) – The parent step of this step. Used to determine a fully-qualified name for this step, and to determine the mode in which to run this step.

• config_file (str or pathlib.Path, optional) – The path to the config file that this step was initialized with. Use to determine relative path names of other config files.

• **kws (dict) – Additional parameters to set. These will be set as member variables on the new Step instance.

Attributes Summary

class_alias
reference_file_types
spec

Methods Summary

process(input_models)

Run the step.

Attributes Documentation

class_alias = 'skymatch'

reference_file_types: list = []

spec

# General sky matching parameters:
skymethod = option('local', 'global', 'match', 'global+match', 'user', default='match') # sky computation method
match_down = boolean(default=True) # adjust sky to lowest measured value?
subtract = boolean(default=False) # subtract computed sky from image data?
skylist = string(default=None) # Filename pointing to list of (imagename skyval) pairs

# Image's bounding polygon parameters:
stepsize = integer(default=None) # Max vertex separation

# Sky statistics parameters:
skystat = option('median', 'midpt', 'mean', 'mode', default='mode') # sky statistics
dqbits = string(default='~DO_NOT_USE+NON_SCIENCE') # "good" DQ bits
lower = float(default=None) # Lower limit of "good" pixel values
upper = float(default=None) # Upper limit of "good" pixel values
nclip = integer(min=0, default=5) # number of sky clipping iterations
lsigma = float(min=0.0, default=4.0) # Lower clipping limit, in sigma
usigma = float(min=0.0, default=4.0) # Upper clipping limit, in sigma
binwidth = float(min=0.0, default=0.1) # Bin width for 'mode' and 'midpt' `skystat`, in sigma

# Memory management:
in_memory = boolean(default=True) # If False, preserve memory using temporary files

Methods Documentation

process(input_models)

Run the step.

Parameters:

input_models (Any data type readable into a ModelLibrary, e.g. an asn file) – An association of datamodels to input.

Returns:

A library of datamodels with the skymatch step applied.

Return type:

ModelLibrary