plot_delchi

Context: plotting

Synopsis

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

Syntax

plot_delchi(id=None, replot=False, overplot=False, clearwindow=True,
**kwargs)

Description

This function displays the residuals (data - model) divided by the error, for a data set.

Examples

Example 1

Plot the residuals for the default data set, divided by the error value for each bin:

>>> plot_delchi()

Example 2

Overplot the values from the 'core' data set on those from the 'jet' dataset:

>>> plot_delchi('jet')
>>> plot_delchi('core', overplot=True)

Example 3

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')

PARAMETERS

The parameters for this function are:

Parameter	Type information	Definition
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 to `plot_delchi` . The default is False .
overplot	bool, optional	If True then add the data to an existing plot, otherwise create a new plot. The default is False .
clearwindow	bool, optional	Should the existing plot area be cleared before creating this new plot (e.g. for multi-panel plots)?

Notes

The additional arguments supported by `plot_delchi` are the same as the keywords of the dictionary returned by `get_data_plot_prefs` .

The ylog setting is ignored, and the Y axis is drawn using a linear scale.

Changes in CIAO

Changed in CIAO 4.12

The Y axis is now always drawn using a linear scale.

Bugs

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