Some tables have constant values associated with them; these may represent such things as the epoch at which observations were taken, the name of the catalogue, an angular resolution associated with all observations, or any number of other things. Such constants are known as table parameters and can be viewed and modified in the Parameter Window. The values of such parameters can be referenced in algebraic expressions as follows:
param$
.
ucd$
. Any punctuation marks in the
UCD should be replaced by underscores, and a trailing underscore
is interpreted as a wildcard. See Section 7.1 for
more discussion.
utype$
. Any punctuation marks in the
Utype should be replaced by underscores. See Section 7.1 for
more discussion.
There are also a couple of special values:
long
(8-byte integer);
when using it in certain expressions you may find it necessary to convert
it to an int
(4-byte integer) using the
toInteger()
function.