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: plotting


Plot the unconvolved source model


plot_source( [id], [lo=None, hi=None, replot=False, overplot=False] )


The plot_source function plots the unconvolved source model in the current units of the spectral analysis, set by the set_analysis command (either channel, energy, or wavelength space). Any filter applied to the associated data with notice or ignore are not used; set the 'lo' and 'hi' parameters to change the displayed range. Use the plot_model command to plot the convolved model amplitudes.

The plot_source command supports the 'factor' setting of set_analysis (see "ahelp set_analysis"). This means that calling plot_source while the set_analysis 'factor' setting is '1' will plot E F(E) versus E in keV, or lambda f(lambda) versus lambda in Angstroms, depending on which units are set for the spectral analysis. A set_analysis 'factor=2' setting will plot E^2 F(E) versus E, or lambda^2 f(lambda) versus lambda.

Argument Default Description
id 1 (can be changed, see "ahelp get_default_id") the id of the dataset to plot
lo None lower limit of the plot in the same units as the data (energy [keV] or wavelength [A]). The default value of None means that the minimum value from the response file is used (ENERG_LO).
hi None upper limit of the plot in the same units as the data (energy [keV] or wavelength [A]). The default value of None means that the maximum value from the response file is used (ENERG_HI).
replot False should previously-calculated arrays be used to create the plot?
overplot False If True then add the data to the current plot, otherwise erase the frame and create a new plot.

The plot is displayed in a ChIPS plotting window. If there is no plotting window open, one is created. If a plotting window exists, the overplot parameter value determines whether the new plot is overlaid on any existing plots in the window or if the window is cleared before the plot is drawn.

ChIPS commands may be used within Sherpa to modify plot characteristics and create hardcopies; refer to the ChIPS website for information.

Plotting Multiple Objects

To plot multiple Sherpa objects - e.g. data, model, fit, residuals - in a single window, use the plot command.

Example 1

sherpa> plot_source()
sherpa> log_scale(Y_AXIS)

Using the default settings, plot the unconvolved source model. The limits for the plot will be calculated from the response file. The ChIPS command log_scale is used to change the Y axis to a logarithmic scale.

Example 2

sherpa> plot_source(lo=0.3, hi=7.0)

Plot the unconvolved source model for the default dataset (normally 1), using limits of 0.3-7.0 keV (the analysis setting is assumed to be "energy" for this example).

Example 3

sherpa> plot_source( 2, overplot=True )

Plot the unconvolved source model for data id 2, overlaying it on any existing plot.

Example 4

sherpa> plot_source("src", hi=5.0)

The unconvolved source model for data set "src" is plotted with an upper limit of 5.0 keV.

Example 5

sherpa> set_analysis("energy", factor=1)
sherpa> plot_source()

The unconvolved source model for data set 1 is plotted as E F(E) versus E, in units of photons/sec/cm^2 versus keV.

Example 6

sherpa> set_analysis("wavelength", factor=2)
sherpa> plot_source(2)

The unconvolved source model for data set 2 is plotted as lambda^2 f(lambda) versus lambda, in units of Angstroms photons/sec/cm^2 versus Angstroms.


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

See Also

get_data_prof, get_data_prof_prefs, get_delchi_prof, get_delchi_prof_prefs, get_fit_prof, get_model_prof, get_model_prof_prefs, get_resid_prof, get_resid_prof_prefs, get_source_prof, get_source_prof_prefs, plot_chart_spectrum, prof_data, prof_delchi, prof_fit, prof_fit_delchi, prof_fit_resid, prof_model, prof_resid, prof_source
get_arf_plot, get_bkg_plot
list_model_ids, show_bkg_model, show_bkg_source
add_model, add_user_pars, clean, create_model_component, 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
get_energy_flux_hist, get_photon_flux_hist, get_split_plot, plot, plot_arf, plot_bkg, plot_chisqr, plot_data, plot_delchi, plot_energy_flux, plot_fit, plot_model, plot_model_component, plot_order, plot_photon_flux, plot_ratio, plot_resid, plot_source_component, set_xlinear, set_xlog, set_ylinear, set_ylog
delete_psf, load_conv, plot_kernel
save_delchi, save_resid
get_chisqr_plot, get_delchi_plot
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.