read_xstable_model

sherpa.astro.xspec.read_xstable_model(modelname, filename, etable=False)

Create a XSPEC table model.

XSPEC additive (atable, [1]), multiplicative (mtable, [2]), and exponential (etable, [3]) table models are supported.

Changed in version 4.16.0: Parameters with negative DELTA values are now made frozen, to match XSPEC. Support for models which use the ESCALE keyword has been added. The hard_max and hard_min values of the redshift parameter (for those models that support it) can now be changed. This should be done with care as it could cause memory corruption or a crash.

Changed in version 4.14.0: The etable argument has been added to allow exponential table models to be used.

Parameters:

• modelname (str) – The identifier for this model component.

• filename (str) – The name of the FITS file containing the data, which should match the XSPEC table model definition [4].

• etable (bool, optional) – Set if this is an etable (as there’s no way to determine this from the file itself). Defaults to False.

Returns:

tablemodel

Return type:

XSTableModel instance

Notes

There is no support for table models that provide multiple spectra per parameter: that is, those with the NXFLTEXP keyword set.

References

[1]

https://heasarc.gsfc.nasa.gov/docs/xanadu/xspec/manual/XSmodelAtable.html

[2]

https://heasarc.gsfc.nasa.gov/docs/xanadu/xspec/manual/XSmodelMtable.html

[3]

https://heasarc.gsfc.nasa.gov/docs/xanadu/xspec/manual/XSmodelMtable.html

[4]

https://heasarc.gsfc.nasa.gov/docs/heasarc/ofwg/docs/general/ogip_92_009/ogip_92_009.html

Examples

Load in the XSPEC table model from the file ‘bbrefl_1xsolar.fits’ and create a model labelled ‘xmdl’, which is then returned:

>>> mdl = read_xstable_model('xmdl', 'bbrefl_1xsolar.fits')
>>> print(mdl)

When the file is an etable model the etable parameter must be set:

>>> emdl = read_xstable_model('xmdl', 'etable.fits', etable=True)
>>> print(emdl)