Chandra X-Ray Observatory
Skip to the navigation links
Last modified: 13 March 2017

How can I set the coordinate system to be used in the analysis of my image data?

By default, image data sets are read into Sherpa in image ('logical') coordinates. The coordinate system for the analysis may be changed to physical or world using the set_coord command:

sherpa> load_image(2, "image_bin50.fits")
sherpa> get_coord(2)
sherpa> set_coord(2, "wcs")

Note: the physical coordinates of non-Chandra data sets may not be recognized in the current version of Sherpa; see the load_image bug page for details.

Last modified: 13 March 2017
Smithsonian Institute Smithsonian Institute

The Chandra X-Ray Center (CXC) is operated for NASA by the Smithsonian Astrophysical Observatory. 60 Garden Street, Cambridge, MA 02138 USA.   Email: Smithsonian Institution, Copyright © 1998-2017. All rights reserved.