contour_ratio

sherpa.astro.ui.contour_ratio(id: IdType | None = None, replot=False, overcontour=False, **kwargs) → None

Contour the ratio of data to model.

The ratio image is formed by dividing the data by the current model, including any PSF. The preferences are the same as contour_data.

Parameters:

  • id (int, str, or None, optional) – The data set that provides the data and model. 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 contour_ratio. The default is False.

  • overcontour (bool, optional) – If True then add the data to an existing plot, otherwise create a new contour plot. The default is False.

See also

get_ratio_contour

Return the data used by contour_ratio.

get_default_id

Return the default data set identifier.

contour

Create one or more plot types.

sherpa.astro.ui.set_coord

Set the coordinate system to use for image analysis.

Examples

Plot the ratio from the default data set:

>>> contour_ratio()

Overplot the ratio on the residuals:

>>> contour_resid('img')
>>> contour_ratio('img', overcontour=True)