### 4 Configuration options

GAIA has many options that can be defined when starting it up. These are best set using the Startup options... window located in the File menu, but you also define these on the command-line:



 option Meaning -autoscale Auto scale image to fit window (disables zoom) -autofit Auto fit new images to window -always_merge Merge primary and extension headers -blank_color Colour for blank pixels -catalog Open windows for the given catalogs on startup -check_for_cubes Check input files to see if they are cubes (1) -component NDF component to display on startup -component The NDF component (data, variance or quality) -default_cmap Change the default colour map -demo_mode Make the demo toolbox available -extended_precision Show milliarcsecond readout precision -float_panel Detach the control panel -focus_follows_mouse Image and entry focus follows mouse pointer -force_degrees Display decimal degrees in main window readout -font_scale A scale for non-pixel display fonts -geometry A geometry for the main window -ident A string to add to the window titles -interop_menu Reveal the Interop menu for SAMP interactions -image_background Colour for the background of the main image -isize Search box for centroiding (9) -linear_cartesian Assume CAR projections are a linear mapping -maxshift Maximum shift when centroiding (5.5) -pick_zoom_factor Default scale factor used in pick object window -pixel_indices Display NDF pixel indices as X,Y -quiet_exit Issue a warning before exiting GAIA (0) -show_hdu_chooser Automatically show the HDU chooser -transient_tools Make toolboxes transient -transient_spectralplot Make spectral plot window transient -visual X visual (pseudocolor, truecolor, visual id) -with_colorramp Display a colour ramp -with_pan_window Display a pan window -with_zoom_window Display a zoom window 

The full list of options can be seen using the --help option.

So for instance if you wanted to float the control panel (useful for smaller displays) and have a grey default colourmap. Then start using the command:

% gaia image_name -default_cmap ramp -float_panel 1

Or alternatively to save some space without floating the panel try:

% gaia image_name -with_zoom_window 0 -with_pan_window 0

(1 means true and 0 false).

If you’d like the toolboxes to remain on top of the display window they are associated with then set the transient_tools option to 1 (the precise behaviour you get depends on your window manager14).

If you prefer to point at the image and text entry fields before using the keyboard, rather than having to click in them first, then use the command:

% gaia image_name -focus_follows_mouse 1

Some additional configuration options are only available using environment variables. The most useful of these is the GAIA_TEMP_DIR variable, that defines a directory that will be used for writing most temporary files. The default is to write these into the current directory which can be a problem when working on read-only data.

#### 4.1 Proxy servers

Access to the World Wide Web may be restricted (by a firewall or maybe just site policy), so that it is only available through a “web cache” or proxy server. If you are in this situation you’ll need to configure GAIA so that its remote catalogue access will work.

To do this, start up GAIA, select the Data-Servers menu and choose any remote catalogue. Now in the catalogue window select the Options menu and choose the Proxies... item.

Now fill in the two fields (consult your system administrator if you’re unclear what to enter here) and press OK.

#### 4.2 Add new colour and intensity maps

The default set of colour and intensity maps used in GAIA can be extended by adding new ones to the ˜/.skycat/colormaps directory. Colour maps are simple text files with three columns, each column represents the Red, Greed and Blue fractions for values in the range 0 to 255, so the file should have 256 rows and three columns of values in the range 0 to 1. Intensity maps should also be in this format, but just have one column with values in the range 0 to 1. Finally colour maps should have the file extension .lasc and intensity maps .iasc. The basename of the files should be unique and not match those of any existing colour and intensity maps, if they do so then the existing maps will be superceded. The maps themselves can only be found in the View menu window Colors....

14Even if you don’t have transient_tools set, window managers can still cause many perceived problems dealing with toolboxes. Make sure that you have ‘autoraise’ and ‘autoraise on first focus’ type options switched off, if you feel that toolboxes and dialogs unnecessarily take charge of things like the focus.