get_num_par¶
- sherpa.ui.get_num_par(id=None)¶
Return the number of parameters in a model expression.
The
get_num_par
function returns the number of parameters, both frozen and thawed, in the model assigned to a data set.- Parameters
id (int or str, optional) – The data set containing the model expression. If not given then the default identifier is used, as returned by
get_default_id
.- Returns
npar – The number of parameters in the model expression. This sums up all the parameters of the components in the expression, and includes both frozen and thawed components.
- Return type
- Raises
sherpa.utils.err.IdentifierErr – If no model expression has been set for the data set (with
set_model
orset_source
).
See also
get_num_par_frozen
Return the number of frozen parameters.
get_num_par_thawed
Return the number of thawed parameters.
set_model
Set the source model expression for a data set.
Examples
Return the total number of parameters for the default data set:
>>> print(get_num_par())
Find the number of parameters for the model associated with the data set called “jet”:
>>> njet = get_num_par('jet')