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Last modified: 22 December 2022


Bugs: ds9, dax, and XPA

Table of Contents




Enabling the Preserve During Load preferences can lead to regions being shifted by 0.5 pixel in both X and Y directions.

CIAO users should not enable either of the following options in their preferences:

Menus and Buttons → File → Menu → Preserve During Load → Pan
Menus and Buttons → File → Menu → Preserve During Load → Region

Due to the way CIAO starts ds9, having these preferences enabled leads to a half-pixel shift in regions. This shift accumulates if the region file is saved and re-loaded.

If a user has multiple instances of ds9 running, the dax tasks which use xpa calls will not work properly.


You can specify a unique name for each ds9 when it is launched

unix% ds9 -title snrs file_1.fits &
unix% ds9 -title grbs file_2.fits &


Plotting with prism fails in DS9 8.4 / CIAO 4.15 [New] (16 Dec 2022)

When attempting to plot columns using the prism table viewer an error window will appear saying

An internal error has been detected
invalid command name

and the data will not be plotted.

Version 8.4.1 of DS9 can be downloaded from the DS9 home page.

Some of the text boxes are non-functional when ds9 is launched from a sherpa image* command.