Chandra X-Ray Observatory
Skip to the navigation links
Last modified: December 2010

Jump to: Description · Examples · Bugs · See Also

AHELP for CIAO 4.3 Sherpa v1


Context: modeling


Create a new model component


create_model_component( typename, name )


The create_model_component command is an explicit means of setting and naming a model by type. It is called implicitly when the set_source command ("ahelp set_source") is used. The model is created with parameters set to the default values.

  • typename - the type of model to establish; see "ahelp models" for a list of options
  • name - the name for the model. Once assigned, it is in the local variable scope.

This command is equivalent to "" when using the default model automatic assignment function; see "ahelp set_model_autoassign_func" for more information.

Example 1

sherpa> create_model_component("powlaw1d", "p1")
sherpa> list_model_components()

Create an instance of a 1D powerlaw model named "p1". The model is established with the default settings:

sherpa> print(p1)
   Param        Type          Value          Min          Max      Units
   -----        ----          -----          ---          ---      -----
   p1.gamma     thawed            1          -10           10
   p1.ref       frozen            1     -3.4e+38      3.4e+38
   p1.ampl      thawed            1            0      3.4e+38

Example 2

sherpa> create_model_component("bbody", "bb")
sherpa> list_model_components()

Establish a blackbody model named "bb" with the default settings:

sherpa> print(bb)
   Param        Type          Value          Min          Max      Units
   -----        ----          -----          ---          ---      -----     thawed            0            0            1 0 - energy | 1 - wave
   bb.kT        thawed            1          0.1        1e+03        keV
   bb.ampl      thawed            1        1e-20        1e+20

sherpa> print(bb.ampl)
val     = 1
min     = 1e-20
default = 1
max     = 1e+20
units   =
frozen  = False
link    = None


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

See Also

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_order_plot, get_par, get_pileup_model, get_source, get_source_component_image, get_source_component_plot, image_model, image_model_component, image_source, image_source_component, integrate, link, load_table_model, load_user_model, reset, save_model, save_source, set_bkg_model, set_full_model, set_model_autoassign_func, set_pileup_model, set_source, set_xsabund, set_xscosmo, set_xsxsect, set_xsxset
plot_model, plot_model_component, plot_source, plot_source_component
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, get_ratio, get_resid

Last modified: December 2010
Smithsonian Institute Smithsonian Institute

The Chandra X-Ray Center (CXC) is operated for NASA by the Smithsonian Astrophysical Observatory. 60 Garden Street, Cambridge, MA 02138 USA.   Email: Smithsonian Institution, Copyright © 1998-2019. All rights reserved.