get_chisqr_plot

sherpa.astro.ui.get_chisqr_plot(id=None)

Return the data used by plot_chisqr.

Parameters:id (int or str, optional) – The data set. If not given then the default identifier is used, as returned by get_default_id.
Returns:resid_data
Return type:a sherpa.plot.ChisqrPlot instance
Raises:sherpa.utils.err.IdentifierErr – If the data set does not exist or a source expression has not been set.

See also

get_delchi_plot()
Return the data used by plot_delchi.
get_ratio_plot()
Return the data used by plot_ratio.
get_resid_plot()
Return the data used by plot_resid.
plot_chisqr()
Plot the chi-squared value for each point in a data set.

Examples

Return the residual data, measured as chi square, for the default data set:

>>> rplot = get_chisqr_plot()
>>> np.min(rplot.y)
0.0005140622701128954
>>> np.max(rplot.y)
8.379696454792295

Display the contents of the residuals plot for data set 2:

>>> print(get_chisqr_plot(2))

Overplot the residuals plot from the ‘core’ data set on the ‘jet’ data set:

>>> r1 = get_chisqr_plot('jet')
>>> r2 = get_chisqr_plot('core')
>>> r1.plot()
>>> r2.overplot()