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Last modified: December 2009

URL: http://cxc.harvard.edu/sherpa/ahelp/get_data_prof.html
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AHELP for CIAO 4.6 Sherpa v1

get_data_prof

Context: contrib

Synopsis

Return the data used to create the radial or elliptical profile of imaging data.

Syntax

get_data_prof( [id], [model=None, rstep=None, rmin=None, rmax=None,
rlo=None, rhi=None, xpos=None, ypos=None, ellip=None, theta=None,
group_counts=None, group_snr=None, recalc=True] )

Description

The get_data_prof() command calculates the radial - or elliptical - profile of the imaging data and returns an object containing the values. The profile is defined by the existing model compenents, although it is possible to over-ride these values.

Loading the routine

The routine can be loaded into Sherpa by saying:

from sherpa_contrib.profiles import *

Argument options

The argument options are the same as for the prof_data() command - except that the overplot and label arguments are not supported - and are described in its ahelp page.

Fields returned by get_data_prof

The following table lists the fields in the object returned by the get_data_prof() command. These values can also be seen by using the print command on the object:

sherpa> d = get_data_prof(rstep=10)
sherpa> print (d)
Field name Description
xlo The lower-limits of the radial bins
xhi The upper-limits of the radial bins
y The calculated profile value (sum of data / area)
yerr The error on y
xlabel The label for the X axis
ylabel The label for the Y axis
labels The labels giving the profile parameters
title The plot title
histo_prefs The preferences for the plot

Example 1

sherpa> d10 = get_data_prof(group_snr=10)
sherpa> d20 = get_data_prof(group_snr=20)
sherpa> erase()
sherpa> add_histogram(d10.xlo, d10.xhi, d10.y, d10.yerr)
sherpa> add_histogram(d20.xlo, d20.xhi, d20.y, d20.yerr, ["line.color",
"red"])
sherpa> set_plot_xlabel(d10.xlabel)
sherpa> set_plot_ylabel(d10.ylabel)

Two profiles of the same dataset are calculated; d10 uses a signal-to-noise ratio of 10 and d20 a value of 20. The return values are then used to plot up the profiles using ChIPS commands to compare the plots (the d20 results are shown in green).

Example 2

sherpa> prof_data("src1", group_counts=100)
sherpa> da = get_data_prof(recalc=False)
sherpa> prof_data("src2", rlo=da.xlo, rhi=da.xhi, overplot=True)
sherpa> set_histogram(["symbol.color", "orange"])

A profile is calculated and displayed for the dataset "src1". The bin edges from this are then used to create a profile for the dataset "src2", which is overlain on the first plot using orange symbols. Note that recalc is set to False in the call to get_data_prof() to avoid unnescessary re-calculations.

Bugs

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

See Also

contrib
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, sherpa_profiles
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_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 2009
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