# ResampleStep¶

class jwst.resample.ResampleStep(name=None, parent=None, config_file=None, _validate_kwds=True, **kws)[source]

Resample input data onto a regular grid using the drizzle algorithm.

Parameters

input (DataModel or Association) – Single filename for either a single image or an association table.

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 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

Methods Summary

 get_drizpars(ref_filename, input_models) Extract drizzle parameters from reference file. process(input) This is where real work happens.

Attributes Documentation

reference_file_types = ['drizpars']
spec = "\n pixfrac = float(default=1.0)\n kernel = string(default='square')\n fillval = string(default='INDEF')\n weight_type = option('exptime', default='exptime')\n single = boolean(default=False)\n blendheaders = boolean(default=True)\n "

Methods Documentation

get_drizpars(ref_filename, input_models)[source]

Extract drizzle parameters from reference file.

This method extracts parameters from the drizpars reference file and uses those to set defaults on the following ResampleStep configuration parameters:

pixfrac = float(default=None) kernel = string(default=None) fillval = string(default=None) weight_type = option(‘exptime’, default=None)

Once the defaults are set from the reference file, if the user has used a resample.cfg file or run ResampleStep using command line args, then these will overwerite the defaults pulled from the reference file.

process(input)[source]

This is where real work happens. Every Step subclass has to override this method. The default behaviour is to raise a NotImplementedError exception.