get_ratio_image
- sherpa.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:
sherpa.utils.err.DataErr – If the data set is not 2D.
sherpa.utils.err.IdentifierErr – If the data set does not exist or a source expression has not been set.
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()