; DOINVERS
;---------------------------------------------------------------
;! selects opposite of normal function
;# ADVERB ANALYSIS
;-----------------------------------------------------------------------
;;  Copyright (C) 1995, 2020
;;  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
;-----------------------------------------------------------------------
;---------------------------------------------------------------
DOINVERS  LLLLLLLLLLLLUUUUUUUUUUUU CCCCCCCCCCCCCCCCCCCCCCCCCCCCC
----------------------------------------------------------------
DOINVERS
Type: Adverb   (logical,  > 0  =>  true)
Use:  If true, do the reverse of the "normal" operation.
Null Value:  false (-1)
Tasks:
Verbs:
   EVLA..........Puts the list of eVLA antennas in the current file on
                 stack.  DOINVERS > 0 returns non-EVLA antennas.
   HSA...........Puts the list of HSA antennas in the current file on
                 stack.  DOINVERS > 0 returns non-HSA antennas.
   HUEWEDGE......Show a wedge on the TV suitable for TVHUEINT displays.
                 DOINVERS > 0 puts the intensity wedge on the long axis
                 and the hue on the short axis.
   IMSTAT........Returns statistics of a sub-image.  DOINVERS > 0 does
                 statistics outside BLC to TRC.
   MAXFIT........Returns pixel position and image intensity at a maximum.
                 DOINVERS > 0 fits a peak in the negative of the image,
                 i.e. it fits a hole in the image.
   TVANOT........Verb to load anotation to the TV image or graphics.
                 DOINVERS > 0 writes the string vertically.
   TVSTAT........Find the mean and RMS in a blotch region on the TV.
                 DOINVERS > 0 finds statistics outside the blotch
                 region.
   VLA...........Puts the list of VLA antennas in the current file on
                 stack.  DOINVERS > 0 lists the non-VLA antennas.
   VLBA..........Puts the list of VLBA antennas in the current file on
                 stack.  DOINVERS > 0 returns non-VLBA stations.
Procedures:
   TVMAXFIT......Displays fit pixel positions and intensity at maxima on
                 TV.  DOINVERS > 0 fits a peak in the negative of the
                 image, i.e. it fits a hole in the image.
Tasks:
   BLANK.........Blank regions inside (DOINVERS false) or outside
                 (DOINVERS true) blotch regions drawn on the TV.
                 Ignores DOINVERS on other blanking methods.
   BLSUM.........Determine image statistics inside (DOINVERS false) or
                 outside (DOINVERS true) blotch regions drawn on the TV.
   IMEAN.........Displays the mean & extrema and plots histogram of an
                 image.  DOINVERS > 0 uses the region outside BLC - TRC
                 for the histogram.
   ISPEC.........Plots and prints spectrum of region of a cube.
                 DOINVERS true causes the spectrum to be found using
                 only pixels outside the specified CLBOXes.
   PBCOR.........Task to apply or correct an image for a primary beam.
                 DOINVERS > 0 causes the image to be multiplied by the
                 primary beam,
   PRTAB.........Prints any table-format extension file.  DOINVERS > 0
                 causes only those rows not matching specified values
                 to be printed.
   RSPEC.........Plots and prints spectrum of rms of a cube.  DOINVERS >
                 0 computes the rms outside the specified CLBOXes.
   SPCOR.........Task to correct an image for a primary beam and spectral
                 index.  DOINVERS > 0 multiplies the image by the
                 primary beam and undoes the spectral-index correction.
   TAPLT.........Plots data from a Table extension file.
   TVCPS.........Task to copy a TV screen-image to a PostScript file.
                 DOINVERS > 0 plolts only those rows that do not match
                 the selection criteria.
   VLANT.........Applies VLA/EVLA antenna position corrections from OPs
                 files.  DOINVERS > 0 undoes the correction.
   XYDIF.........Find/apply X minus Y linear polarization phase
                 difference.  DOINVERS > 0 adds 180 degrees to the
                 solutions.
----------------------------------------------------------------
