; OPCODE
;---------------------------------------------------------------
;! General adverb, defines an operation
;# ADVERB GENERAL UTILITY
;-----------------------------------------------------------------------
;;  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
;-----------------------------------------------------------------------
;---------------------------------------------------------------
OPCODE    LLLLLLLLLLLLUUUUUUUUUUUU CCCCCCCCCCCCCCCCCCCCCCCCCCCCC
----------------------------------------------------------------
OPCODE
Type: Adverb (String*4)
Use:  To specify the operation to be used by a task or verb.
Null Value: '   ' has various meanings depending on the task.
      When '    ' is listed below, it means that the task gives
      some special meaning to OPCODE = '    ' or at least to
      any OPCODE value not in the list.

Verbs with supported OPCODE values:
  PUTVALUE...Store a pixel value at specified position in image:
             'BLNK', '    '

Procedures with supported OPCODE values:
  VLBACPOL......Procedure to calibrate cross-polarization delays.
                'AVIF'
  VLBAKRGP......Fringe fit phase referenced data and apply calibration.
                ' ', 'ZPHS', 'ZRAT',' 'ZDEL'
  VLBAKRNG......Fringe fit data and apply calibration.
                ' ', 'ZPHS', 'ZRAT',' 'ZDEL'
  VLBAMPCL......Calculates and applies manual instrumental phase
                calibration.  ' ', 'CALI', 'CALP', 'MERG'
  VLBAPCOR......Calculates and applies instrumental phase calibration.
                ' ', 'CALI', 'CALP', 'MERG'

Tasks with supported OPCODE values:
  AFARS.........Is used after FARS to determine position and value of the
                maximum.   ' ', 'CMPL'
  AFILE.........Sorts and edits MkIII correlator A-file.
                'SORT', 'EDIT'
  ANBPL.........Plots and prints uv data converted to antenna based
                values.   ' ', ALIF', 'ALST', 'ALSI'
  APCAL.........Apply TY and GC tables to generate an SN table.
                ' ', 'PLOT', 'GRID', 'GRDR', 'OPAC', 'OPCR'. 'LESQ'
  APGPS.........Apply GPS-derived ionospheric corrections.
                'IFR ', 'DISP'
  APVC..........Deconvolve images with van Cittert algorithm:
                'VC  ', 'TL  ', 'ST  ', 'WT  ', 'PC  '
                '+VC ', '+TL ', '+ST ', '+WT ', '+PC '
  AVTP..........Position tape to desired file:
                'REWI', 'EOT ', 'AVFI'
  BAKLD.........Read all files of a catalog entry from BAKTP tape:
                'LOAD', 'PRNT'
  BAKTP.........Write all files of a catalog entry to tape in host
                format:   'BACK', 'INIT'
  BLANK.........Blank out selected portions of an image:
                'TVCU', 'FIXW', 'FLTW', 'MOMW', 'FLUW', 'SELC',
                'IN2C', 'RADI'
  BLAPP.........Applies baseline-based fringe solutions a la BLAPP.
                'SOLV', 'CAL ', 'MK4 '
  BLING.........Find residual rate and delay on individual baselines.
                'INDE', 'VLBA', 'MK3 ', 'RATE'
  BPCOR.........Correct BP table.  ' ',
                'FUNC', 'HANN', 'BOXC', GAUS', 'SINC', 'BMED', 'SPEC
  CANDY.........User-definable (paraform) task to create an AIPS image.
  CAPLT.........Plots closure amplitude and model from CC file.
                ' ', 'INDE'
  CCMOD.........Generate clean components to fit a model:
                'DISK', 'GAUS', 'POIN'
  CLCAL.........Merge & smooth SN tables, apply to CL tables:
                'MERG', 'CALI', 'CALP'
  CLCOR.........Apply corrections to the calibration CL table
                'POLR', 'PHAS', 'RATE', 'OPAC', 'ADEL', 'GAIN', 'POGN',
                'CLOC', 'PANG', 'PONT', 'IONS', 'ANTP', 'ANTC', 'PCAL',
                'PCFX', 'SBDL', 'MBDL', 'SSLO', 'ANAX', 'ATMO', 'TROP',
                'DISP', 'SUND', 'EOPS'. 'IONO'
  COMB..........Combine two images:
                'SUM ', 'DIV ', 'SPIX', 'POLI', 'POLA', 'MULT', 'OPTD',
                'CLIP', 'REAL', 'IMAG', 'MEAN', 'RM  ', 'POLC', 'SUMM'
  CONVL.........Convolve image with gaussian or another image:
                'GAUS', 'GMOD', 'IMAG', 'IMAC', 'DCON', 'DGAU'
  CSCOR.........Apply specified corrections to CS tables:
                'OPAC', 'GAIN', 'PTRA', 'PTDC'
  DCONV.........Deconvolve a gaussian from an image:
               'IN2C', 'UNWT'
  DFCOR.........Applies user-selected corrections to the calibration CL
                table.   'ATMO' only
  DTCHK.........Task to check results of a test using simulated data.
                'TABC', 'UVUN'
  ELINT.........Determines and removes gain dependence on elevation.
                'POLE', 'POLZ', ;PWR ', 'PWRN'
  FARAD.........Add ionospheric Faraday rotation to CL table:
                ' ', 'TEC ', 'F0F2', 'MOD '
  FFT...........Take Fourier transform of image(s):
                'UVRE', 'UVCX', 'MARE', 'MACX', 'UVIR', 'UVIX'
  FGTAB.........Writes frequency-range flags to a text file to be read by
                UVFLG.  ' '. 'ANTE'
  FITLD.........Reads FITS files to load images or UV (IDI or UVFITS)
                data to disk.   'VT',  'ALL', 'VALL'
  FLGIT.........Flags data based on the rms of the spectrum.
                ' '. 'MWFL'
  IMMOD.........Add images of model objects to an image:
                'GAUS', 'DISK', 'RECT', 'SPHE', 'EXPD', 'POIN'
  KRING.........Fringe fit data to determine antenna calibration, delay,
                rate.  ' ', 'ZPHS', 'ZRAT', 'ZDEL'
  MATHS.........Operate on image with choice of math functions:
                'SIN ', 'COS ', 'TAN ', 'ASIN', 'ACOS', 'ATAN', 'LOG ',
                'ALOG', 'LOGN', 'EXP ', 'POLY', 'POWR', 'MOD ', 'ABS '
  MODIM.........Adds images of model objects to image cubes in IQU
                polarization.
                'GAUS', 'DISK', 'RECT', 'SPHE', 'EXPD', 'POIN'
  MOVE..........Task to copy or move data from one user or disk to
                another.   ' ', 'MOVE', 'DUPL, 'COPD'
  MWFLT.........Apply linear & non-linear filters to images:
                'MW  ', 'ALFA', 'MODE', 'NRML', 'MAX', 'MIN', 'ROW'
  NINER.........Apply various 3x3 area operaters to an image:
                'NINE', 'NORT', 'NE  ', 'EAST', 'SE  ', 'SOUT',
                'SW  ', 'WEST', 'NW  ', 'MSK1', 'MSK2', 'MSK3',
                'SOBL', 'KRSH', 'WALL'
  OBEDT.........Task to flag data of orbiting antennas.
                'DIST', 'VEL ', 'SUNS', 'ECLB', 'ECLE'
  OBPLT.........Plot columns of an OB table.
                'TIME', 'DIST', 'VEL ', ANG1', 'BECL', 'EECL', 'ORIE'
  OOSUB.........Subtracts/divides a model from/into a uv data base.
                ' ', 'DIV ', 'MODL'
  PASTE.........Pastes a selected subimage of one image into another.
                'REPL', 'ADD'
  PATGN.........Create a user-specified test pattern:
                'ZONE', 'GAUS', 'LRTZ', 'RADI', 'POLY', 'BEAM', 'INVB'
  PHSRF.........Perform phase-referencing within a spectral line
                database.   ' ', 'PHSR', 'A&P', 'PHBL', 'APBL'
  PLOTC.........Plots color schems used by 3-color plot tasks.
                'ALAN', 'ALTI', 'ALIF', 'ALST', 'ALSI'
  POLCO.........Correct polarization maps for Ricean bias:
                'ZERO', '    '
  POLSN.........Make a SN table from cross polarized fringe fit.
                ' ', 'AVIF'
  PRTSY.........Task to print statistics from the SY table.
                'SCAN', 'IFS', 'ANTS', 'SORC', 'EFFS', ' '
  QUACK.........Flag beginning or end portions of UV-data scans:
               'END ', 'BEG '
  RMSD..........Calculate rms for each pixel using data in a box around
                the pixel.  'RMS', 'MEAN', 'BLAN', 'MAD', 'MEDI'
  RSPEC.........Plots and prints spectrum of rms of a cube.
                ' '. 'WEIT'
  SCLIM.........Operates on an image with a choice of mathematical
                functions.  'LOG', 'ALOG', 'LOGN', 'EXP', 'POWR',
                'LN', 'NE', 'SQ', 'NQ', 'LG', 'NG'
  SLCOL.........Collate slice data and models:
                'MODL', 'SLVL'
  SNBLP.........Plots selected contents of SN or CL files on a baseline
                basis.   ' ', 'IFDF', 'IFRA,, 'ALIF', 'ALST', 'ALSI'
  SNCOR.........Applies user-selected corrections to the calibration SN
                table.  'AVRT', 'CLPA', 'CLPP', 'CLPD', 'CLPR', 'CLPW',
                'XFER', 'ZPHS', 'ZRAT', 'ZDEL', 'MULA', 'REFP, ''CPRT',
                'CPSN', 'PCOP', 'PNEG', 'NORM'
  SNIFS.........Plots selected contents of SN, TY, SY, PC or CL files by
                IF.    ' ', 'ALAN', 'ALTI'
  SNPLT.........Plots selected contents of SN, SY, TY, PC or CL files
                versus time. ' ', 'IFDF', 'IFRA,, 'ALIF', 'ALST', 'ALSI'
  SPFIX.........Makes cube from input to and output from SPIXR spectral
                index.   ' '. 'DIFF'
  STACK.........Task to co-add a set of 2-dimensional images with
                weighting.   ' ', 'MEDI', 'CUBE', 'MEDC'
  SUBIM.........Task to select a subimage from up to a 7-dim. image.
                ' ', 'AVE', 'SUM', 'MIN', MAX'
  SYVSN.........Plots selected SY/TY data with SN solution values versus
                time.   'PHAS', 'DELA', 'AMP'
  TAFFY.........User definable task to operate on an image.
  TARS..........Simulation of Faraday rotation synthesis (mainly task
                FARS).  ' ', 'CMPL', 'ZERO'
  TFILE.........Sorts and edits MkIII correlator UNIX-based A-file.
                'SORT', 'EDIT'
  TVCPS.........Task to copy a TV screen-image to a PostScript file.
                ' ', 'COL', 'GREY', 'GRAY', 'B&W', 'COLB'
  UJOIN.........Modifies UV data converting IFs to spectral channels.
                ' ', 'DIFF'
  USUBA.........Assign subarrays within a uv-data file.
                ' ', 'SCAN', 'AUTO'
  UVADD.........Combines two matching uv data sets.
                'ADD', 'SUBT', 'MULT', 'DIV'
  UVAVG.........Average or merge 'BT' or 'TB' sorted UV data:
                'MERG', '    '
  UVDIF.........Print differences between two UV data sets:
                'CLIP', 'UVBX', '    '
  UVFIT.........Fit gaussian or spheres to UV data:
                'GAUS', 'SPHE'
  UVFLG.........Flag selected UV data on disk:
                'FLAG', 'UFLG', 'REAS', 'WILD'
  UVFND.........Print UV data selected to search for problems:
                'CLIP', 'FRNG', 'UVBX', 'VCLP', 'WTUV'
  UVGIT.........Fits source models to uv data.
                'GAUS', 'SPHE'
  UVHGM.........Plot statistics (histograms) of uv data files:

  UVMTH.........Correct one uv dataset with the average of another:
                'ADD ', 'SUB ', 'MULT', 'DIV '
  UVPOL.........Modifies UV data to make complex image and beam.
                'WEIG', 'DATA'
  UVRFI.........Mitigate RFI by Fourier transform or fitting the circle.
                'CEXP', 'CIRC'
  UVSUB.........Subtract clean components from a uv data base:
                ' ', 'DIV ', 'DIV4', 'MODL'
  VPFLG.........Resets flagging to all or all corss-hand whenever some
                are flagged.   ' ', 'CROS'
  VPLOT.........Plots uv data and model from CC file.   ' ', 'IFRA'
  XSMTH.........Smooth image data on the x axis only:
                'SMOT', 'INTE'
  XSUM..........Sum or average image data on the x axis only:
                'SUM ', 'AVER'
  XYMOD.........Compute linear polarization point source model, applies
                to data.   ' ', 'MODL', 'SUBT'
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