tmatch2
: Crossmatches 2 tables
tmatch2
is an efficient and highly configurable
tool for crossmatching pairs of tables.
It can match rows between tables on the basis of their relative position
in the sky, or alternatively using many other criteria such as
separation in some isotropic or anisotropic Cartesian space,
identity of a key value, or some combination of these;
the full range of match criteria is discussed in Section 6.1.
You can choose whether you want to identify all the matches or
only the closest,
and what form the output table takes, for instance matched rows only,
or all rows from one or both tables, or only the unmatched rows.