Last modified: December 2023

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AHELP for CIAO 4.16 Sherpa


Context: modeling


Create a model component.


create_model_component(typename=None, name=None)

typename - str
name - str


Model components created by this function are set to their default values. Components can also be created directly using the syntax , such as in calls to `set_model` and `set_source` (unless you have called `set_model_autoassign_func` to change the default model auto-assignment setting).


Example 1

Create an instance of the powlaw1d model called pl , and then freeze its gamma parameter to 2.6.

>>> create_model_component("powlaw1d", "pl")
>>> pl.gamma = 2.6
>>> freeze(pl.gamma)

Example 2

Create a blackbody model called bb, check that it is reconized as a component, and display its parameters:

>>> create_model_component("bbody", "bb")
>>> list_model_components()
>>> print(bb)
>>> print(bb.ampl)


The parameters for this function are:

Parameter Definition
typename The name of the model. This should match an entry from the return value of `list_models` , and defines the type of model.
name The name used to refer to this instance, or component, of the model. A Python variable will be created with this name that can be used to inspect and change the model parameters, as well as use it in model expressions.


This function can over-write an existing component. If the over-written component is part of a source expression - as set by `set_model` - then the model evaluation will still use the old model definition (and be able to change the fit parameters), but direct access to its parameters is not possible since the name now refers to the new component (this is true using direct access, such as mname.parname , or with `set_par` ).


See the bugs pages on the Sherpa website for an up-to-date listing of known bugs.

See Also

get_bkg_chisqr_plot, get_bkg_delchi_plot, get_bkg_fit_plot, get_bkg_model_plot, get_bkg_plot, get_bkg_ratio_plot, get_bkg_resid_plot, get_bkg_source_plot
list_model_ids, show_bkg_model, show_bkg_source
add_model, add_user_pars, clean, delete_bkg_model, delete_model, delete_model_component, get_model, get_model_autoassign_func, get_model_component, get_model_component_image, get_model_component_plot, get_model_plot, get_num_par, get_num_par_frozen, get_num_par_thawed, get_order_plot, get_par, get_pileup_model, get_source, get_source_component_image, get_source_component_plot, get_source_contour, get_source_image, get_source_plot, get_xsabund, get_xscosmo, get_xsxsect, get_xsxset, image_model, image_model_component, image_source, image_source_component, integrate, link, load_table_model, load_template_interpolator, load_template_model, load_user_model, normal_sample, reset, save_model, save_source, set_bkg_model, set_bkg_source, set_full_model, set_model, set_model_autoassign_func, set_pileup_model, set_source, set_xsabund, set_xscosmo, set_xsxsect, set_xsxset, t_sample, uniform_sample
get_cdf_plot, get_pdf_plot, get_pvalue_plot, get_pvalue_results, plot_cdf, plot_model, plot_model_component, plot_pdf, plot_pvalue, plot_scatter, plot_source, plot_source_component, plot_trace
delete_psf, load_conv
save_delchi, save_resid
calc_chisqr, calc_energy_flux, calc_model_sum, calc_photon_flux, calc_source_sum, calc_stat, eqwidth
contour_model, contour_ratio, contour_resid