get_source

sherpa.ui.get_source(id: IdType | None = None) → Model

Return the source model expression for a data set.

This returns the model expression created by set_model or set_source. It does not include any instrument response.

Parameters:

id (int, str, or None, optional) – The data set containing the source expression. If not given then the default identifier is used, as returned by get_default_id.

Returns:

model – This can contain multiple model components. Changing attributes of this model changes the model used by the data set.

Return type:

a sherpa.models.Model object

See also

delete_model

Delete the model expression from a data set.

get_model

Return the model expression for a data set.

get_model_pars

Return the names of the parameters of a model.

get_model_type

Describe a model expression.

list_model_ids

List of all the data sets with a source expression.

sherpa.astro.ui.set_bkg_model

Set the background model expression for a data set.

set_model

Set the source model expression for a data set.

set_full_model

Define the convolved model expression for a data set.

show_model

Display the source model expression for a data set.

Examples

Return the source expression for the default data set, display it, and then find the number of parameters in it:

>>> src = get_source()
>>> print(src)
>>> len(src.pars)
5

Set the source expression for data set ‘obs2’ to be equal to the model of data set ‘obs1’ multiplied by a scalar value:

>>> set_source('obs2', const1d.norm * get_source('obs1'))