Chandra X-Ray Observatory
	(CXC)
Skip to the navigation links
Last modified: December 2013

URL: http://cxc.harvard.edu/sherpa/ahelp/plot_ratio.html
Jump to: Description · Examples · Bugs · See Also


AHELP for CIAO 4.6 Sherpa v2

plot_ratio

Context: plotting

Synopsis

Plot the (data/model) ratio

Syntax

plot_ratio( [id], [replot=False, overplot=False] )

Description

The plot_ratio command plots the ratio of dataset divided by model (data/model).

  • id - the id of the dataset to use; if not given, uses the default dataset id (id=1 by default, see "ahelp get_default_id")
  • replot - should the cached arrays be used in the plot? False (default)=do the calculation, True=redisplay the existing values
  • overplot - should the new plot be overlaid in the plotting window? False (default)=clear the window, True=overplot on any existing plots

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_ratio()

Plot the ratio for the default dataset.

Example 2

sherpa> plot_ratio("src", overplot=True)

Plot the ratio for the "src" dataset, overlaying on any existing plots.

Bugs

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

See Also

contrib
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
data
get_arf_plot, get_bkg_plot
modeling
normal_sample, t_sample, uniform_sample
plotting
get_energy_flux_hist, get_lrt_plot, get_lrt_results, get_photon_flux_hist, get_pvalue_plot, get_pvalue_results, get_split_plot, plot, plot_arf, plot_bkg, plot_cdf, plot_chisqr, plot_data, plot_delchi, plot_energy_flux, plot_fit, plot_lrt, plot_model, plot_model_component, plot_order, plot_pdf, plot_photon_flux, plot_pvalue, plot_resid, plot_scatter, plot_source, plot_source_component, plot_trace, set_xlinear, set_xlog, set_ylinear, set_ylog
psfs
plot_kernel
statistics
get_chisqr_plot, get_delchi_plot
visualization
contour_resid

Last modified: December 2013
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:   cxcweb@head.cfa.harvard.edu Smithsonian Institution, Copyright © 1998-2014. All rights reserved.