ResampleStep

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

Bases: JwstStep

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

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

`check_list_pars`(vals, name[, min_vals])	Validate step parameters that may take a 2-element list.
`get_drizpars`()	Load all drizzle-related parameter values into kwargs list.
`process`(input_data)	Run the resample step on the input data.

Attributes Documentation

class_alias = 'resample'

reference_file_types: list = []

spec

pixfrac = float(min=0.0, max=1.0, default=1.0)  # Pixel shrinkage factor
kernel = option('square','gaussian','point','turbo','lanczos2','lanczos3',default='square')  # Flux distribution kernel
fillval = string(default='NAN')  # Output value for pixels with no weight or flux
weight_type = option('ivm', 'exptime', None, default='ivm')  # Input image weighting type
output_shape = int_list(min=2, max=2, default=None)  # [x, y] order
crpix = float_list(min=2, max=2, default=None)  # 0-based image coordinates of the reference pixel
crval = float_list(min=2, max=2, default=None)  # world coordinates of the reference pixel
rotation = float(default=None)  # Output image Y-axis PA relative to North
pixel_scale_ratio = float(default=1.0)  # Ratio of output to input pixel scale.
pixel_scale = float(default=None)  # Absolute pixel scale in arcsec
output_wcs = string(default='')  # Custom output WCS. Overrides other WCS parameters if provided.
single = boolean(default=False)  # Resample each input to its own output grid
blendheaders = boolean(default=True)  # Blend metadata from inputs into output
in_memory = boolean(default=True)  # Keep images in memory
enable_ctx = boolean(default=True)  # Compute and report the context array
enable_err = boolean(default=True)  # Compute and report the err array
report_var = boolean(default=True)  # Report the variance array

Methods Documentation

static check_list_pars(vals, name, min_vals=None)[source]

Validate step parameters that may take a 2-element list.

Parameters:

vals (list or None) – Values to validate.
name (str) – Parameter name.
min_vals (list, optional) – Minimum allowed values for the parameter. Must have 2 values.

Returns:

values – The validated list of values.

Return type:

list

Raises:

ValueError – If the values do not have expected values.

get_drizpars()[source]

Load all drizzle-related parameter values into kwargs list.

Returns:: kwargs – Dictionary of drizzle parameters
Return type:: dict

process(input_data)[source]

Run the resample step on the input data.

Parameters:: input_data (str, ImageModel, or any asn-type input loadable into ModelLibrary) – Filename pointing to an ImageModel or an association, or the ImageModel or association itself.
Returns:: The final output data. If the single parameter is set to True, then this is a single ImageModel; otherwise, it is a ModelLibrary.
Return type:: ModelLibrary or ImageModel

Notes

When supplied via output_wcs, a custom WCS overrides other custom WCS parameters such as output_shape (now computed from by output_wcs.bounding_box) and crpix.