Here are some general examples. They could be used to define synthetic columns or (where numeric) to define values for one of the axes in a plot.
(first + second) * 0.5
sqrt(variance)
radiansToDegrees(DEC_radians)
degreesToRadians(RA_degrees)
parseInt($12)
parseDouble(ident)
toString(index)
toShort(obs_type)
toDouble(range)
or
(short) obs_type
(double) range
hmsToRadians(RA1950)
dmsToRadians(decDeg,decMin,decSec)
radiansToDms($3)
radiansToHms(RA,2)
min(1000, max(value, 0))
jmag == 9999 ? NULL : jmag
NULL_jmag ? 9999 : jmag
psfCounts[2]
RA > 100 && RA < 120 && Dec > 75 && Dec < 85
$2*$2 + $3*$3 < 1
skyDistance(ra0,dec0,degreesToRadians(RA),degreesToRadians(DEC))<15*ARC_MINUTE
index <= 100
index % 10 == 0
equals(SECTOR, "ZZ9 Plural Z Alpha")
equalsIgnoreCase(SECTOR, "zz9 plural z alpha")
startsWith(SECTOR, "ZZ")
contains(ph_qual, "U")
matches(SECTOR, "[XYZ] Alpha")
(_1 && _2) && ! _3
! NULL_ellipticity