Source code for sunkit_spex.legacy.fitting.io
"""
The ``io`` module contains code to read instrument specific spectral data.
"""
from astropy.io import fits
__all__ = ["_read_pha", "_read_arf", "_read_rmf"]
[docs]
def _read_pha(file):
"""
Read a .pha file and extract useful information from it.
Parameters
----------
file : `str`, `file-like` or `pathlib.Path`
A .pha file (see `~astropy.fits.io.open` for details).
Returns
-------
`tuple`
The channel numbers, counts, and the livetime for the observation.
"""
with fits.open(file) as hdul:
data = hdul[1].data
header_for_livetime = hdul[0].header
return data["channel"], data["counts"], header_for_livetime["LIVETIME"]
[docs]
def _read_arf(file):
"""
Read a .arf file and extract useful information from it.
Parameters
----------
file : `str`, `file-like` or `pathlib.Path`
A .arf file (see `~astropy.fits.io.open` for details ).
Returns
-------
`tuple`
The low and high boundary of energy bins, and the ancillary response [cm^2] (data['specresp']).
"""
with fits.open(file) as hdul:
data = hdul[1].data
return data["energ_lo"], data["energ_hi"], data["specresp"]
[docs]
def _read_rmf(file):
"""
Read a .rmf file and extract useful information from it.
Parameters
----------
file : `str`, `file-like` or `pathlib.Path`
A .rmf file (see `~astropy.fits.io.open` for details).
Returns
-------
`tuple`
The low and high boundary of energy bins (data['energ_lo'], data['energ_hi']), number of sub-set channels in the energy
bin (data['n_grp']), starting index of each sub-set of channels (data['f_chan']),
number of channels in each sub-set (data['n_chan']), redistribution matrix [counts per photon] (data['matrix']).
"""
with fits.open(file) as hdul:
data = hdul[2].data
return data["energ_lo"], data["energ_hi"], data["n_grp"], data["f_chan"], data["n_chan"], data["matrix"]
