AIPS NRAO AIPS HELP file for IMLOD in 31DEC19



As of Sun Dec 16 19:14:23 2018


IMLOD: Task to store an image from a FITS or IBM-CV tape

INPUTS

INTAPE            0.0       9.0    Input tape drive # (0 => 1)
OUTNAME                            Image name (name)
OUTCLASS                           Image name (class)
OUTSEQ           -1.0    9999.0    Image name (seq. #)
                                      0 => highest unique number
                                     -1 => FITS tape value
OUTDISK           0.0       9.0    Disk drive # (0 => any)
NCOUNT            0.0     999.0    Number of files to load.
DOTABLE          -1.0       1.0    True (1.0) means load tables
NFILES        -9999.0    9999.0    # of files to advance on tape
NMAPS             0.0     999.0    # IBM maps to advance on tape
DATAIN                             Disk file name (FITS only)
ERROR            -1.0       3.0    >= 2 -> do not use AIPS
                                   history in the FITS file

HELP SECTION

IMLOD
Type: Task
Use:  IMLOD loads a map from tape to disk.  The tape format may be the
      "IBM" map format or the FITS format.  The task converts the tape
      map header into the standard form and stores the header in the
      header file.  The map array is then stored in a separate disk
      file in the same catalog location.  The tape is positioned after
      the End-of-file mark for FITS tapes or after the last row for
      IBM tapes.  Thus, for the latter an EOF may be the next record.
      If any TABLES data are found on a FITS tape, they may be
      converted to additional extension files of the image.  This
      applies to Clean Components and other AIPS table files written
      by FITTP and to some general tables written by other systems.
      If IMAGE extensions are present, they are written to separate
      catalog entries, but all TABLES are attached to the primary
      catalog entry.

      IMLOD (and PRTTP, UVLOD, FITLD, TPHEAD) now understand and
      interpret the standard world coordinate system keywords CDi_j
      and PCi_j.  They are used if possible and problems reported.
Adverbs:
  INTAPE......The input tape drive #.  0 => 1.
  OUTNAME.....The output image name (name).  Standard behavior
              with default = the original map file name (FITS),
              the source name, or 'NONE'.
  OUTCLASS....The output image name (class).  Standard behavior
              with default = the original map class (FITS) or a
              class of the form 'STYP  ', where S = (I, Q, U, V)
              Stokes parameter of the image and TYP = (BEM, CLN,
              MAP) for a beam, clean map, or anything else.
              Special combination images (OPTD et al.) are also
              recognized.
  OUTSEQ......The output image name (seq #).  0 => Find the
              lowest number which produces a unique mapname.
              -1 => use the sequence number on the tape (if
              any - works only on tapes written by FITTP).
  OUTDISK.....The disk drive #.  0 => highest with space
  NCOUNT......The number of consecutive files to load from tape.
  DOTABLE.....True (1.0) means load all tables. (FITS only).
  NFILES......# of files to skip on tape before reading data
              1 => start of next file, -1 => start of previous
              file.  0 => not tape movement before read.  Use
              the AIPS verb AVFILE if needed to position at the
              start of the current (or other) file plus TPHEAD
              to make sure you are at the right place.
  NMAPS.......For IBM map format there can be more than map in a
              single tape file.  IMLOD first positions at the
              start of the requested file (with NFILES), then
              advances NMAPS into the file (for IBM format
              only).
  DATAIN......48-character name of the disk file from which to
              read a FITS file.  It must be in the form
                  :
              or
                  :::
              where  is the remote computer name,
               is the environment variable (logical
              name) for the disk area in which the file named
               is stored.   is usually omitted
              when the file is local to the current computer.
  ERROR......>= 2 => do not parse AIPS history cards found in the FITS
             header.  Do not use this option until you have tried IMLOD
             without it.  If you get mysterious errors (usually error 4
             which implies premature end of file), then try IMLOD with
             ERROR set to 2.  For a period of time, UV data sets written
             out with FITAB, read back in, processed, and then written
             out with FITTP could have so many AIPS history records in
             their header as to cause IMLOD to read the data wrongly.

EXPLAIN SECTION

IMLOD:  Task to store an image from a FITS or IBM-CV tape
Documentor: E.B.Fomalont
Related Programs: PRTTP, FITTP, AVTP, MOUNT, DISMOUNT

                        PURPOSE

     IMLOD is the task used to read images from tape to disk in
the format used by AIPS.  There are two tape formats recognized
by AIPS; FITS format and IBM-map format.  FITS format is the
most general and images can be written on tape in this format
from many institutions.  The IBM-map format is an old format
which is compatible with an old tape format used in
Charlottesville. IMLOD is able to distinguish between these two
formats.
     FITTP is the AIPS task which generates a FITS tape from an
image on disk.  IBMTP is the AIPS task which generates an IBM-
map format.  There is very little reason to use IBMTP.
     In FITS, each image is contained in a separate file.  For
spectral-line work the image may consist of many planes.  More
than one image can be loaded with one execution of IMLOD if they
are in consecutive files on the tape.  Certain extension files
may be associated with an image.  At the present time general
tables files and clean-components files written by FITTP will be
read into AIPS using IMLOD.
     FITS format files can be read from a disk file on one of
the AIPS disks.  This uses the adverb DATAIN.

                          COMMENTS

OUTNAME, OUTCLASS, OUTSEQ, OUTDISK
     If OUTNAME is unspecified, the following will be taken:
          Original outname used when writing image
          Source name
           'NONE'
     If OUTCLASS is unspecified, the following will be taken:
          Original outclass used when writing image
          Class of form 'STYP' where S is the Stokes parameter
             and TYP is the type of image
          'IMAP'
     If OUTSEQ = 0
          Lowest available sequence number for the specified
             OUTNAME and OUTCLASS and OUTDISK
     If OUTSEQ = -1
          Original outseq used when writing image
          Lowest available sequence number for the specified
             OUTNAME and OUTCLASS and OUTDISK.

NCOUNT
    Number of consecutive files to load.  If NCOUNT is zero then
    one file will be loaded.

DOTABLES
    If DOTABLES is false (-1) then table files such as CC files
    will not be loaded from tape.  If these files are not
    needed this option can greatly increase loading time.

AIPS