get_ratio_image

sherpa.astro.ui.get_ratio_image(id=None)

Return the data used by image_ratio.

Parameters:

id (int or str, optional) – The data set. If not given then the default identifier is used, as returned by get_default_id.

Returns:

ratio_img – The y attribute contains the ratio values as a 2D NumPy array.

Return type:

a sherpa.image.RatioImage instance

Raises:

See also

get_resid_image

Return the data used by image_resid.

contour_ratio

Contour the ratio of data to model.

image_ratio

Display the ratio (data/model) for a data set in the image viewer.

Examples

Return the ratio data for the default data set:

>>> rinfo = get_ratio_image()