get_delchi_plot

sherpa.astro.ui.get_delchi_plot(id: IdType | None = None, recalc=True)

Return the data used by plot_delchi.

Parameters:

• id (int, str, or None, optional) – The data set. If not given then the default identifier is used, as returned by get_default_id.

• recalc (bool, optional) – If False then the results from the last call to plot_delchi (or get_delchi_plot) are returned, otherwise the data is re-generated.

Returns:

resid_data

Return type:

a sherpa.plot.DelchiPlot instance

Raises:

sherpa.utils.err.IdentifierErr – If the data set does not exist or a source expression has not been set.

See also

get_chisqr_plot

Return the data used by plot_chisqr.

get_ratio_plot

Return the data used by plot_ratio.

get_resid_plot

Return the data used by plot_resid.

plot_delchi

Plot the ratio of residuals to error for a data set.

Examples

Return the residual data, measured in units of the error, for the default data set:

>>> rplot = get_delchi_plot()
>>> np.min(rplot.y)
-2.85648373819671875
>>> np.max(rplot.y)
2.89477053577520982

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

>>> print(get_delchi_plot(2))

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

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