contour_ratio

sherpa.ui.contour_ratio(id=None, **kwargs)

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 or str, 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 exsiting 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)