astrohack.utils.fits

Functions

get_stokes_axis_iaxis(header)	Get which of the axis in the header is the stokes axis
safe_keyword_fetch(header_dict, keyword)	Tries to fetch a keyword from a FITS header / dictionary
read_fits_no_checks(filename)	Brute force reading of a fits file, no checks are performed
read_fits(filename[, header_as_dict])	Reads a square FITS file and do sanity checks on its dimensionality
get_axis_from_fits_header(header, iaxis[, pixel_offset])	Pull axis information from FITS file and store it in a numpy array, ignores rotation in axes.
write_fits(header, imagetype, data, filename, unit[, ...])	Write a dictionary and a dataset to a FITS file
put_resolution_in_fits_header(header, resolution)	Adds resolution information to standard header keywords: BMAJ, BMIN and BPA
put_axis_in_fits_header(header, axis, iaxis, axistype, ...)	Process an axis to create a FITS compatible linear axis description
put_stokes_axis_in_fits_header(header, iaxis)	Inserts a dedicated stokes axis in the header at iaxis

Module Contents

get_stokes_axis_iaxis(header)

Get which of the axis in the header is the stokes axis :param header: FITS header

Returns:

None if no stokes axis is found, iaxis if stokes axis is found

safe_keyword_fetch(header_dict, keyword)

Tries to fetch a keyword from a FITS header / dictionary :param header_dict: FITS header / Dictionary :param keyword: The intended keyword to fetch

Returns:

Keyword value if prensent, None if not present.

read_fits_no_checks(filename)

Brute force reading of a fits file, no checks are performed :param filename: Fits filename

Returns:

FITS header as a dict and associated data

read_fits(filename, header_as_dict=True)

Reads a square FITS file and do sanity checks on its dimensionality :param filename: a string containing the FITS file name/path :param header_as_dict: return header as dictionary

Returns: The FITS header and the associated data array

get_axis_from_fits_header(header, iaxis, pixel_offset=True)

Pull axis information from FITS file and store it in a numpy array, ignores rotation in axes. :param header: FITS header :param iaxis: Which axis is to be fetched from the header. :param pixel_offset: apply one pixel offset

Returns:

numpy array representation of axis, axis type and axis unit

write_fits(header, imagetype, data, filename, unit, origin=None, reorder_axis=True)

Write a dictionary and a dataset to a FITS file :param header: The dictionary containing the header :param imagetype: Type to be added to FITS header :param data: The dataset :param filename: The name of the output file :param unit: to be set to bunit :param origin: Which astrohack mds has created the FITS being written :param reorder_axis: Reorder data axes so that they are compatible with regular FITS ordering

put_resolution_in_fits_header(header, resolution)

Adds resolution information to standard header keywords: BMAJ, BMIN and BPA :param header: The dictionary header to be augmented :param resolution: The lenght=2 array with the resolution elements

Returns: The augmented header dictionary

put_axis_in_fits_header(header: dict, axis, iaxis, axistype, unit, iswcs=True)

Process an axis to create a FITS compatible linear axis description :param header: The header to add the axis description to :param axis: The axis to be described in the header :param iaxis: The position of the axis in the data :param axistype: Axis type to be displayed in the fits header :param unit: Axis unit :param iswcs: Is the axis a part of World Coordinate System for the image?

Returns: The augmented header

put_stokes_axis_in_fits_header(header, iaxis)

Inserts a dedicated stokes axis in the header at iaxis :param header: The header to add the axis description to :param iaxis: The position of the axis in the data

Returns: The augmented header