AIPS HELP file for CLBOX in 31DEC19
As of Tue Dec 11 21:48:10 2018
Type: Adverb (Real(4,50))
Use: An array containing 50 sets of of four numbers that are
normally used to specify areas within which model
sources may be found (e.g. point sources found by Clean).
The number of such areas is normally given by the value
of the NBOXES adverb.
All tasks that use the CLBOX adverb support the definition
of rectangular areas in which the four numbers are the
x and y pixel coordinates of the bottom-left corner
followed by the x and y coordinates of the top-right
corner in pixels. IMAGR, SCMAP and WFCLN also support
the definition of circular areas by setting: a circular
area is specified by setting the first number to -1, the
second to the radius of the circle on pixels and the third
and fourth to the x and y pixel coordinates of the centre.
Null value: 0
Null value assignment varies with the verb or task.