AIPS HELP file for NANS in 31DEC24
As of Fri Sep 13 23:30:07 2024
NANS: Looks for NaNs in an image or a uv data set
INPUTS
INNAME Input file name (name)
INCLASS Input file name (class)
INSEQ 0.0 9999.0 Input file name (seq. #)
INDISK 0.0 9.0 Input file disk unit #
BCOUNT 0.0 Start vis number for search
NCOUNT 0.0 Maximum number lines printed
BLC Bottom left corner of image
TRC Top right corner of image
HELP SECTION
NANS
Task: This task will look through an image or a UV data set for
illegal numbers (NaNs). It prints their locations in the
message window.
For UV data, it counts the number of NaNs in a vis record (1
baseline, 1 time, all polarizations, spectral channels, and
IFs). It counts real and imaginary part separately and so is
likely to count 2 for every complex vis that has gone bad. It
also reports accidental cases of a binary value exactly
matching the value used as a "magic blank".
For images, it can examine a subimage if desired. It will
print detailed info about the location of NaNs for a while,
then less detailed info, and finally only a summary by plane.
Magic blanks are ignored in images (if the header says they
are there) as they are normal and handled properly.
Adverbs:
INNAME.....Input UV or MA file name (name). Standard defaults.
INCLASS....Input UV or MA file name (class). Standard defaults.
INSEQ......Input UV or MA file name (seq. #). 0 => highest.
INDISK.....Disk drive # of input UV or MA file. 0 => any.
BCOUNT.....Start visibility number for search. 0 -> 1.
NCOUNT.....Stop printing after NCOUNT lines - 0 -> 1000.
For images, it will print detailed information about NaNs
until NCOUNT lines have been printed. It will then print
summaries, one row at a time, until another NCOUNT lines
have been printed. At that point it reverts to listing
the number of NaNs in each 2-D plane.
BLC........The bottom left-hand pixel of the sub-image to be
examined. 0's -> 1.
TRC........The top right-hand pixel of the sub-image tobe examined.
0's -> maximum on corresponding axis.
EXPLAIN SECTION