List all the background identifiers for a data set.

A PHA data set can contain multiple background datasets, each identified by an integer or string. This function returns a list of these identifiers for a data set.

Parameters:id (int or str, optional) – The data set to query. If not given then the default identifier is used, as returned by get_default_id.
Returns:ids – The identifiers for the backround data sets for the data set. In many cases this will just be [1].
Return type:array of int or str

See also

List all the response identifiers of a data set.
Load the background of a PHA data set.