As of Sat May 15 15:27:11 2021

NANS: Looks for NaNs in an image or a uv data set


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


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.
  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.