This thread provides an overview of the key components of the ds9 graphical user interface (GUI).
This thread uses Chandra data from an observation of the
Trapezium Cluster (ObsID 1522). The default ds9 GUI is
shown in
The default setup is a "horizontal layout", with the
information panel, panner, magnifier, and buttons displayed
horizontally across the window. This may be changed to
"vertical layout" in the View menu (
Note that the colorbar remained horizontal at the bottom of the display frame. This may be changed with the "vertical colorbar" option in the "View" menu.
The menu bar provides access to all of ds9's capabilities. For a complete description of each menu, refer to the Menu bar section of the Reference Manual.
All ds9 menus can be "torn off" to be a separate window
from the main GUI. To tear off a menu, select the
dashed line, which is the first item of each menu (shown
in
The information panel displays information about the
data file and the values at the cursor position. In
The fields of the information panel can be customized from the "View" menu. Any of the default entries can be removed, and additional fields can be added (e.g. detector coordinates, min/max data values).
The panner allows the user to view areas of the frame
which are outside of the current field of view.
Although the display frame is filled by the data, the
panner indicates that more of the image is
available. Clicking and dragging the viewing bounding
box in the panner - shown in blue in
The panner also contains axes to indicate the directions of North and East and the directions of the physical (x,y) data axes.
The magnifier displays a magnified view of the current
cursor location. The magnifier cursor - the small square
in the center of
The button bar duplicates many of the options available from the menu bar. The buttons provide quick access to change the most frequently-used ds9 actions (e.g. changing the scale and color bar, blinking and tiling frames).
When a category is chosen from the top row, the options
within that category are displayed in the bottom row of
buttons. In
The display frame is the area of ds9 where the FITS
image is shown. In
Multiple frames can be opened in ds9 at the same time.
In
If the display is set back to "single", then the current frame fills the display area. The other frames can be accessed via the "previous" and "next" options in the buttons bar (or from the "Frame" menu).
The "blink" option may also be used with multiple frames. When blink is turned on, ds9 cycles through all the available frames. The blink interval is set in the "Frame → Frame Parameters → Blink Interval" menu.
The colorbar displays the colormap, bias, and contrast settings. The colormap correlates the colors used in the image with the pixel values in the data.
To change the colormap, use the "Color" menu or button. The contrast and bias can be adjusted by right-clicking and dragging on the ds9 display. The "Color → Colormap Parameters" dialog box can also be used to change contrast and bias.
All of the view options described in this thread can be set
and saved as a preference. Open the "Preferences" dialog box
from the "Edit" menu and select the "View" tab, shown in
The "Default" menus are used to set the defaults of the "View" menu and buttons. For instance, uncheck the "Panner" item under "Menu" and the panner won't be displayed when ds9 is launched. (Note that some options require ds9 to be restarted before they take effect.)
After setting the desired preferences, select "Save". User preferences are stored in .ds9.prf. At startup, ds9 looks for the preferences file in the following directory order: ./, $HOME, /usr/local/lib, /opt/local/lib.