5. Explore data
Once we have reduced data, we probably want to look at. In fact, even before we start the reduction, we should look at the raw data in case of issues.
DRAGONS is not an analysis package. But it does offer a basic way to display images.
The display
and inspect
primitives can be used to visually inspect
the data with ds9
. Those are primitives not recipes, yet reduce
can
run individual primitives.
Note
ds9
must be launched by the user ahead of running the primitive.
5.1. Display
To display an image to ds9
:
reduce -r display N20160102S0271_stack.fits
It is possible to display to different buffer in ds9
, eg. to allow
blinking between the frames.
reduce -r display N20160102S0271_stack.fits -p frame=2
5.2. Inspect
It is recommended to inspect the raw data prior to reducing the data. A quick
visual inspection can catch obviously bad data, or flag some frames for
more detailed inspection. Having to run display on each frame individually
would be painful. The primitive inspect
can be used here. It
accepts a list of file and will display each frame in sequence, adding a short
pause between the frames. The length of the pause can be controlled with
the pause
parameter.
reduce -r inspect @stdstar.lis
reduce -r inspect @stdstar.lis -p pause=1