plot_chisqr

sherpa.astro.ui.plot_chisqr(id: IdType | None = None, replot=False, overplot=False, clearwindow=True, **kwargs) → None

Plot the chi-squared value for each point in a data set.

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

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 to plot_chisqr. 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)?

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_default_id

Return the default data set identifier.

plot

Create one or more plot types.

plot_delchi

Plot the ratio of residuals to error for 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.

set_ylinear

New plots will display a linear Y axis.

set_ylog

New plots will display a logarithmically-scaled Y axis.

Examples

Plot the chi-quare values for each point in the default data set:

>>> plot_chisqr()

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

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