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Last modified: December 2013

URL: http://cxc.harvard.edu/sherpa/ahelp/plot_delchi.html
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AHELP for CIAO 4.9 Sherpa v1

plot_delchi

Context: plotting

Synopsis

Plot the delchi residuals of the fit: (data-model)/error

Syntax

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

Description

The plot_delchi command plots the sigma residuals of the fit, defined to be

(data-model) / error

The plot_resid() command will plot

(data - model)

Argument Default Description
id 1 (can be changed, see "ahelp get_default_id") the id of the dataset to plot
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_delchi()

Plot the delchi residuals for the default dataset.

Example 2

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

Plot the delchi residuals of the fit 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_energy_flux, plot_fit, plot_model, plot_model_component, plot_order, plot_pdf, plot_photon_flux, plot_pvalue, plot_ratio, 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:   cxchelp@head.cfa.harvard.edu Smithsonian Institution, Copyright © 1998-2017. All rights reserved.