NIRCAMGrismModel

class jwst.datamodels.NIRCAMGrismModel(init=None, displ=None, dispx=None, dispy=None, invdispl=None, invdispx=None, invdispy=None, orders=None, **kwargs)

Bases: ReferenceFileModel

A model for a reference file of type “specwcs” for NIRCAM WFSS.

This reference file contains the models for wave, x, and y polynomial solutions that describe dispersion through the grism.

Parameters:
displ: `~astropy.modeling.Model`

Nircam Grism wavelength dispersion model

dispx~astropy.modeling.Model

Nircam Grism row dispersion model

dispy~astropy.modeling.Model

Nircam Grism column dispersion model

invdispl~astropy.modeling.Model

Nircam Grism inverse wavelength dispersion model

invdispx~astropy.modeling.Model

Nircam Grism inverse row dispersion model

invdispy~astropy.modeling.Model

Nircam Grism inverse column dispersion model

orders~astropy.modeling.Model

NIRCAM Grism orders, matched to the array locations of the dispersion models

Parameters:
initstr, tuple, ~astropy.io.fits.HDUList, ndarray, dict, None

  • None : Create a default data model with no shape.

  • tuple : Shape of the data array. Initialize with empty data array with shape specified by the.

  • file path: Initialize from the given file (FITS or ASDF)

  • readable file object: Initialize from the given file object

  • ~astropy.io.fits.HDUList : Initialize from the given ~astropy.io.fits.HDUList.

  • A numpy array: Used to initialize the data array

  • dict: The object model tree for the data model

schemadict, str (optional)

Tree of objects representing a JSON schema, or string naming a schema. The schema to use to understand the elements on the model. If not provided, the schema associated with this class will be used.

memmapbool

Turn memmap of FITS/ASDF file on or off. (default: False).

pass_invalid_valuesbool or None

If True, values that do not validate the schema will be added to the metadata. If False, they will be set to None. If None, value will be taken from the environmental PASS_INVALID_VALUES. Otherwise the default value is False.

strict_validationbool or None

If True, schema validation errors will generate an exception. If False, they will generate a warning. If None, value will be taken from the environmental STRICT_VALIDATION. Otherwise, the default value is False.

validate_on_assignmentbool or None

Defaults to ‘None’. If None, value will be taken from the environmental VALIDATE_ON_ASSIGNMENT, defaulting to ‘True’ if no environment variable is set. If ‘True’, attribute assignments are validated at the time of assignment. Validation errors generate warnings and values will be set to None. If ‘False’, schema validation occurs only once at the time of write. Validation errors generate warnings.

validate_arraysbool

If True, arrays will be validated against ndim, max_ndim, and datatype validators in the schemas.

ignore_missing_extensionsbool

When False, raise warnings when a file is read that contains metadata about extensions that are not available. Defaults to True.

kwargsdict

Additional keyword arguments passed to lower level functions. These arguments are generally file format-specific. Arguments of note are:

  • FITS

    skip_fits_update - bool or None

    DEPRECATED True to skip updating the ASDF tree from the FITS headers, if possible. If None, value will be taken from the environmental SKIP_FITS_UPDATE. Otherwise, the default value is True.

Attributes Summary

reftype

schema_url

The schema URI to validate the model against.

Methods Summary

populate_meta()

to_fits()

Write a data model to a FITS file.

validate()

Convenience function to be run when files are created.

Attributes Documentation

reftype = 'specwcs'
schema_url = 'http://stsci.edu/schemas/jwst_datamodel/specwcs_nircam_grism.schema'

The schema URI to validate the model against. If None, only basic validation of required metadata properties (filename, model_type) will occur.

Methods Documentation

populate_meta()
to_fits()

Write a data model to a FITS file.

Parameters:
initfile path or file object
args, kwargs

Any additional arguments are passed along to astropy.io.fits.writeto.

validate()

Convenience function to be run when files are created. Checks that required reference file keywords are set.