aud may also be used to answer,
for example, the question:
"Which are the coordinates of the red giant stars?".
The next item will answer to the question:
"Which red giants do not have coordinates in the database?" More generally, the syntax
aud -t "type 1" "type 2"
is used to look for data for stars contained in a normal datafile in the database.
It takes the star numbers in the file containing the data corresponding to the data type "type 1" and extracts the data corresponding to the data type defined by "type 2".
aud -t gk coo displays the coordinates (type coo) for the red
giants (type gk).
aud -t vsn mk displays the spectral types (type mk) for the stars
that appear in the file containing the Vsini.