; SUMZE
;---------------------------------------------------------------
;! Task to sum overlapping, sequentially-numbered images
;# TASK IMAGING
;-----------------------------------------------------------------------
;;  Copyright (C) 1995
;;  Associated Universities, Inc. Washington DC, USA.
;;
;;  This program is free software; you can redistribute it and/or
;;  modify it under the terms of the GNU General Public License as
;;  published by the Free Software Foundation; either version 2 of
;;  the License, or (at your option) any later version.
;;
;;  This program is distributed in the hope that it will be useful,
;;  but WITHOUT ANY WARRANTY; without even the implied warranty of
;;  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;;  GNU General Public License for more details.
;;
;;  You should have received a copy of the GNU General Public
;;  License along with this program; if not, write to the Free
;;  Software Foundation, Inc., 675 Massachusetts Ave, Cambridge,
;;  MA 02139, USA.
;;
;;  Correspondence concerning AIPS should be addressed as follows:
;;         Internet email: aipsmail@nrao.edu.
;;         Postal address: AIPS Project Office
;;                         National Radio Astronomy Observatory
;;                         520 Edgemont Road
;;                         Charlottesville, VA 22903-2475 USA
;-----------------------------------------------------------------------
;---------------------------------------------------------------
SUMZE     LLLLLLLLLLLLUUUUUUUUUUUU CCCCCCCCCCCCCCCCCCCCCCCCCCCCC
SUMZE    Task to sum overlapping, sequentially-numbered images
USERID     -32000.0     32000.0    User ID. 0 => current user,
                                     32000 => any user.
INNAME                             First image name (name)
INCLASS                            First image name (class)
INSEQ           1.0      9999.0    First image name (seq. #)
IN2SEQ          1.0       999.0    Final seq # in image set
IN3SEQ          1.0      9999.0    Change of seq # between incl.
INDISK                             Image set disk unit #
OUTNAME                            Output image name (name)
OUTCLASS                           Output image name (class)
OUTSEQ         -1.0      9999.0    Output image name (seq #)
                                     0 => highest unique.
OUTDISK                            Output image disk unit #
BLC             0.0      2048.0    Bottom left corner 0 => 1
TRC             0.0      2048.0    Top right corner 0 => max
FACTOR                             Mult. factor of sum. 0=> #
                                   of input images (ie average)
BADDISK                            Disks to avoid for scratch.
----------------------------------------------------------------
SUMZE: Task to create a sum/avg file including blanks as zeros.
Type: Task
Use:  SUMZE adds together a number of maps, all multiplied by
      a common factor, to form an output map.  The set of images
      must all have the same INNAME and INCLASS and the INSEQ
      must be equally spaced.  Note explain file for diffs w.
      SUMIM
Adverbs:
  USERID......User ID of owner of the image.  0 => current user,
                 32000 => any user.
  INNAME......Name of first image(name).     Standard defaults.
  INCLASS.....Name of first image(class).    Standard defaults.
  INSEQ.......Name of first image(seq. #).   0 => highest.
  IN2SEQ......Final seq. # for image set.    no default.
  IN3SEQ......Change of seq # for set of images.  0 => 1.
              Thus, a DO LOOP over the seq. # is formed
                DO I = INSEQ, IN2SEQ, IN3SEQ
  INDISK......Disk drive # of all input images.  0 => any
  OUTNAME.....Name of summed image(name).    Standard defaults.
  OUTCLASS....Name of summed image(class).   Standard defaults.
  OUTSEQ......Name of summed image(seq. #).  0 => highest unique
  OUTDISK.....Disk drive # for output image. 0 => highest with
              space
  BLC.........Bottom left corner all input images
  TRC.........Top right corner all input images
  FACTOR......Factor by which to multiply all maps before
              adding. If FACTOR .EQ. 0.0  a factor of
              (number of maps) will be used.
  BADDISK.....Disks to avoid for the scratch files.
----------------------------------------------------------------
SUMZE
Type: Task
Use:  SUMZE adds together a number of maps, all multiplied by
      a common factor, to form an output map.  The set of images
      must all have the same INNAME and INCLASS and the INSEQ
      must be equally spaced.
      Difference with SUMIM:
        Any blank is taken to be a zero, so:
          1) map1_i=1.5 + map2_i= blnk yields 1.5 for the sum
            when FACTOR=1
          2) map1_i=1.5 _ map2_i = blnk yields 0.75 for the average
            when FACTOR=0

          Note that all blanks are converted to zeros in this
          process.

          To for a real average using right number of points,
          first run SUMZE with FACTOR = 1, then run SUMWT to
          form the weights file, then use COMB (sum/weights)
          to make the average.
      **blc,trc seem to be ignored (holdover from sumim)