get_exposure

sherpa.astro.ui.get_exposure(id: IdType | None = None, bkg_id: IdType | None = None)

Return the exposure time of a PHA data set.

The exposure time of a PHA data set is taken from the EXPTIME keyword in its header, but it can be changed once the file has been loaded.

Parameters:

idint, str, or None, optional

The identifier for the data set to use. If not given then the default identifier is used, as returned by get_default_id.

bkg_idint, str, or None, optional

Set to identify which background component to use. The default value (None) means that the time is for the source component of the data set.

Returns:

exposurenumber

The exposure time, in seconds.

See also

get_areascal

Return the fractional area factor of a PHA data set.

get_backscal

Return the area scaling of a PHA data set.

set_exposure

Change the exposure time of a PHA data set.

Examples

Return the exposure time for the default data set.

>>> t = get_exposure()

Return the exposure time for the data set with identifier 2:

>>> t2 = get_exposure(2)

Return the exposure time for the first background component of data set “core”:

>>> tbkg = get_exposure('core', bkg_id=1)