load_xstable_model

sherpa.astro.ui.load_xstable_model(modelname, filename, etable=False) → None

Load a XSPEC table model.

Create an additive (‘atable’, [1]), multiplicative (‘mtable’, [2]), or exponential (‘etable’, [3]) XSPEC table model component. These models may have multiple model parameters.

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.

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

Parameters:
modelnamestr

The identifier for this model component.

filenamestr

The name of the FITS file containing the data, which should match the XSPEC table model definition [4].

etablebool, optional

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

Raises:
sherpa.utils.err.ImportErr

If XSPEC support is not enabled.

sherpa.utils.err.IOErr

If the XSPEC table model is not supported by Sherpa.

See also

load_conv

Load a 1D convolution model.

load_psf

Create a PSF model

load_template_model

Load a set of templates and use it as a model component.

load_table_model

Load tabular or image data and use it as a model component.

set_model

Set the source model expression for a data set.

set_full_model

Define the convolved model expression for a data set.

Notes

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

NASA’s HEASARC site contains a link to community-provided XSPEC table models.

References

Examples

Load in the XSPEC table model from the file ‘bbrefl_1xsolar.fits’ and create a model component labelled ‘xtbl’, which is then used in a source expression:

>>> load_xstable_model('xtbl', 'bbrefl_1xsolar.fits')
>>> set_source(xsphabs.gal * xtbl)
>>> print(xtbl)

Load in an XSPEC etable model:

>>> load_xstable_model('etbl', 'etable.mod', etable=True)