get_bkg

sherpa.astro.ui.get_bkg(id=None, bkg_id=None)

Return the background for a PHA data set.

The object returned by the call can be used to query and change properties of the background of data set.

Parameters:

• id (int or str, optional) – The data set. If not given then the default identifier is used, as returned by get_default_id.
• bkg_id (int or str, optional) – The identifier for this background, which is needed if there are multiple background estimates for the source.

Returns:

data

Return type:

a sherpa.astro.data.DataPHA object

Raises:

• sherpa.utils.err.ArgumentErr – If the data set does not contain a PHA data set.
• sherpa.utils.err.IdentifierErr – If no data set is associated with this identifier.

See also

get_data()

Return the data set by identifier.

load_bkg()

Load the backgreound from a file and add it to a PHA data set.

set_bkg()

Set the background for a PHA data set.

Examples

>>> bg = get_bkg()

>>> bg = get_bkg('flare', 2)