image_ratio

sherpa.astro.ui.image_ratio(id=None, newframe=False, tile=False)

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

This function displays the ratio data/model for a data set.

The image viewer is automatically started if it is not already open.

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

  • newframe (bool, optional) – Create a new frame for the data? If False, the default, then the data will be displayed in the current frame.

  • tile (bool, optional) – Should the frames be tiles? If False, the default, then only a single frame is displayed.

Raises

sherpa.utils.err.IdentifierErr – If the data set does not exist or a source expression has not been set.

See also

get_ratio_image

Return the data used by image_ratio.

image_close

Close the image viewer.

image_data

Display a data set in the image viewer.

image_fit

Display the data, model, and residuals for a data set in the image viewer.

image_model

Display the model for a data set in the image viewer.

image_open

Open the image viewer.

image_resid

Display the residuals (data - model) for a data set in the image viewer.

image_source

Display the model for a data set in the image viewer.

Notes

Image visualization is optional, and provided by the DS9 application.

Examples

Display the ratio (data/model) for the default data set.

>>> image_ratio()