plot_delchi
- sherpa.astro.ui.plot_delchi(id: IdType | None = None, replot=False, overplot=False, clearwindow=True, **kwargs) None
Plot the ratio of residuals to error for a data set.
This function displays the residuals (data - model) divided by the error, for a data set.
Changed in version 4.12.0: The Y axis is now always drawn using a linear scale.
- 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
.replot (bool, optional) – Set to
True
to use the values calculated by the last call toplot_delchi
. The default isFalse
.overplot (bool, optional) – If
True
then add the data to an existing plot, otherwise create a new plot. The default isFalse
.clearwindow (bool, optional) – Should the existing plot area be cleared before creating this new plot (e.g. for multi-panel plots)?
- 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_default_id
Return the default data set identifier.
plot
Create one or more plot types.
plot_chisqr
Plot the chi-squared value for each point in a data set.
plot_ratio
Plot the ratio of data to model for a data set.
plot_resid
Plot the residuals (data - model) for a data set.
set_xlinear
New plots will display a linear X axis.
set_xlog
New plots will display a logarithmically-scaled X axis.
Notes
The additional arguments supported by
plot_delchi
are the same as the keywords of the dictionary returned byget_data_plot_prefs
.The ylog setting is ignored, and the Y axis is drawn using a linear scale.
Examples
Plot the residuals for the default data set, divided by the error value for each bin:
>>> plot_delchi()
Overplot the values from the ‘core’ data set on those from the ‘jet’ dataset:
>>> plot_delchi('jet') >>> plot_delchi('core', overplot=True)
Additional arguments can be given that are passed to the plot backend: the supported arguments match the keywords of the dictionary returned by
get_data_plot_prefs
. The following sets error bars to be orange and the marker to be a circle (larger than the default one):>>> plot_delchi(ecolor='orange', marker='o')