; GRCHAN
;---------------------------------------------------------------
;! specifies the TV graphics channel to be used
;# ADVERB TV
;-----------------------------------------------------------------------
;;  Copyright (C) 1995, 2008, 2020
;;  Associated Universities, Inc. Washington DC, USA.
;;
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;;  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.
;;
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;;  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;;  GNU General Public License for more details.
;;
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;;  MA 02139, USA.
;;
;;  Correspondence concerning AIPS should be addressed as follows:
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;;         Postal address: AIPS Project Office
;;                         National Radio Astronomy Observatory
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;-----------------------------------------------------------------------
GRCHAN    LLLLLLLLLLLLUUUUUUUUUUUU CCCCCCCCCCCCCCCCCCCCCCCCCCCCC
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GRCHAN
Type: Adverb  (Real)
Use:   TV graphics channel to use.  GR2CHAN is used when two graphics
       channels need to be specified.  XAS supports 8 graphics channels
       the last of which is used as a black background.  Note that the
       graphics channels may be on or off separately, but they scroll
       together.
Null value: 0   usually means use multiple colors in plotting but other
                defaults are also used.
Verbs:
   COSTAR........Verb to plot a symbol at given position on top of a TV
                 image.
   CURVALUE......Displays image intensities selected via the TV cursor.
   DELBOX........Verb to delete boxes with TV cursor & graphics display.
   DFILEBOX......Verb to delete Clean boxes with TV cursor & write to
                 file.
   DRAWBOX.......Verb to draw Clean boxes on the display.
   FILEBOX.......Verb to reset Clean boxes with TV cursor & write to file.
   GRBLINK.......Verb which blinks 2 TV graphics planes.
   GRCLEAR.......Clears the contents of the specified TV graphics
                 channels.
   GREAD.........Reads the colors of the specified TV graphics channel.
   GROFF.........Turns off specified TV graphics channel(s).
   GRON..........Turns on specified TV graphics channel(s).
   GWRITE........Sets the colors of the specified TV graphics channel.
   HUEWEDGE......Show a wedge on the TV suitable for TVHUEINT displays.
   MFITSET.......Gets adverbs for running IMFIT and JMFIT.
   OFFSCROL......Verb which deactivates scroll of an image.
   TVACOMPS......Verb to add slice model components directly on TV
                 graphics.
   TVAGUESS......Verb to re-plot slice model guess directly on TV
                 graphics.
   TVAMODEL......Verb to add slice model display directly on TV graphics.
   TVANOT........Verb to load anotation to the TV image or graphics.
   TVARESID......Verb to add slice model residuals directly on TV
                 graphics.
   TVASLICE......Verb to add a slice display on TV graphics from slice
                 file.
   TVCOMPS.......Verb to display slice model components directly on TV
                 graphics.
   TVGUESS.......Verb to display slice model guess directly on TV
                 graphics.
   TVILINE.......Verb to draw a straight line on an image on the TV.
   TVLABEL.......Verb to label the (map) image on the TV.
   TVLAYOUT......Verb to label the holography image on the TV with panel
                 layout.
   TVLINE........Verb to load a straight line to the TV image or graphics.
   TVMODEL.......Verb to display slice model directly on TV graphics.
   TVRESID.......Verb to display slice model residuals directly on TV
                 graphics.
   TVSCROL.......Shift position of image on the TV screen.
   TVSLICE.......Verb to display slice file directly on TV.
   TVSTAR........Verb to plot star positions on top of a TV image.
   TVWLABEL......Put a label on the wedge that you just put on the TV.
Procedures:
   LINIMAGE......Build image cube from multi-IF data set.
   TVALL.........Procedure loads image to TV, shows labeled wedge,
                 enhances.
   TVCOLORS......Sets adverb PLCOLORS to match the TV (DOTV=1) usage.
Tasks:
   ALVAR.........Plots the Allan Variance statistic of a UV data set.
   ANBPL.........Plots and prints uv data converted to antenna based
                 values.
   APCAL.........Apply TY and GC tables to generate an SN table.
   BLPLT.........Plots BLCAL tables in 2 dimensions as function of
                 baseline and IF.
   BPEPL.........Plots bandpass tables overlaying multiple times like
                 BPEDT.
   BPERR.........Print and plot BPASS closure outputs.
   BPLOT.........Plots bandpass tables in 2 dimensions as function of
                 time.
   BSTST.........Graphical display of solutions to frequency-switched
                 data.
   CAPLT.........Plots closure amplitude and model from CC file.
   CCNTR.........Generate a contour plot file from an image with CC or MF
                 plotted.
   CLPLT.........Plots closure phase and model from CC file.
   CNTR..........Generate a contour plot file or TV plot from an image.
   CONPL.........Plots AIPS gridding convolution functions.
   DELZN.........Determines residual atmosphere depth at zenith and clock
                 errors.
   DFTPL.........Plots DFT of a UV data set at arbitrary point versus
                 time.
   ELFIT.........Plots/fits selected contents of SN, TY, SY, PC or CL
                 files.
   ELINT.........Determines and removes gain dependence on elevation.
   EVAUV.........Subtracts & divides a model into UV data, does statistics
                 on results.
   FGPLT.........Plots selected contents of FG table.
   FRMAP.........Task to build a map using fringe rate spectra.
   FRPLT.........Task to plot fringe rate spectra.
   GAL...........Determine parameters from a velocity field.
   GCPLT.........Plots gain curves from text files.
   GREYS.........Plots images as contours over multi-level grey.
   IMEAN.........Displays the mean & extrema and plots histogram of an
                 image.
   IMRMS.........Plot IMEAN rms answers.
   IMVIM.........Plots one image's values against another's.
   IRING.........Integrates intensity / flux in rings / ellipses.
   ISPEC.........Plots and prints spectrum of region of a cube.
   KNTR..........Make a contour/grey plot file from an image w multiple
                 panels.
   LOCIT.........Fits antenna locations from SN-table data.
   PANEL.........Convert HOLOG output to panel adjustment table.
   PBEAM.........Fits the analytic function to the measured values of the
                 beam.
   PCHIS.........Generates a histogram plot file from text input, e.g.
                 from PCRMS.
   PCNTR.........Generate plot file with contours plus polarization
                 vectors.
   PCPLT.........Plots pulse-cal tables in 2 dimensions as function of
                 time.
   PDPLT.........Plots selected contents of PD tables.
   PFPL1.........Paraform Task to generate a plot file: (does grey scale).
   PFPL2.........Paraform Task to generate a plot file: (slice intensity).
   PFPL3.........Paraform Task to generate a plot file: (does histogram).
   PLCUB.........Task to plot intensity vs x panels on grid of y,z pixels.
   PLOTC.........Plots color schems used by 3-color plot tasks.
   PLOTR.........Basic task to generate a plot file from text input.
   PLROW.........Plot intensity of a series of rows with an offset.
   POSSM.........Task to plot total and cross-power spectra.
   PROFL.........Generates plot file for a profile display.
   PRTAN.........Prints the contents of the ANtenna extension file.
   RFLAG.........Flags data set based on time and freq rms in fringe
                 visibilities.
   RM2PL.........Plots spectrum of a pixel with RMFIT fit.
   RSPEC.........Plots and prints spectrum of rms of a cube.
   SERCH.........Finds line signals in transposed data cube.
   SL2PL.........Task to convert a Slice File to a Plot File.
   SNBLP.........Plots selected contents of SN or CL files on a baseline
                 basis.
   SNFIT.........Fits parabola to SN amplitudes and plots result.
   SNIFS.........Plots selected contents of SN, TY, SY, PC or CL files by
                 IF.
   SNPLT.........Plots selected contents of SN, SY, TY, PC or CL files
                 versus time.
   SOUSP.........Fits source spectral index from SU table or adverbs.
   SPRMS.........Plots spectral statistics of a selected subset of a uv
                 data set.
   SYVSN.........Plots selected SY/TY data with SN solution values versus
                 time.
   TAPLT.........Plots data from a Table extension file.
   TARPL.........Plot input and output text files of the TARS task.
   TVPL..........Display a plot file on the TV.
   UVHGM.........Plots statistics of uv data files as histogram.
   UVHOL.........Prints holography data from a UV data base with
                 calibration.
   UVPLT.........Plots data from a UV data base in multiple ways.
   UVRMS.........Computes statistics of a selected subset of a uv data
                 set.
   VPLOT.........Plots uv data and model from CC file.
   WETHR.........Plots selected contents of WX tables, flags data based on
                 WX.
   XBASL.........Fits and subtracts nth-order baselines from cube (x
                 axis).
   XG2PL.........Plots spectrum of a pixel with XGAUS/AGAUS and
                 ZEMAN/ZAMAN fits.
   XPLOT.........Plots image rows one at a time on the graphics or TV
                 screen.
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