Skip to the navigation links
Last modified: 14 November 2023


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 &