AIPS NRAO AIPS HELP file for EDITR in 31DEC18



As of Mon Oct 15 5:35:24 2018


EDITR: Interactive baseline-oriented UV data editor using the TV

INPUTS

INNAME                             Input UV data (name)
INCLASS                            Input UV data (class)
INSEQ                              Input UV data (seq. #)
INDISK                             Input UV data disk drive #
SOURCES                            Source list
QUAL            -10.0              Calibrator qualifier -1=>all
CALCODE                            Calibrator code '    '=>all
TIMERANG                           Time range to use
SELBAND                            Bandwidth to select (kHz)
SELFREQ                            Frequency to select (MHz)
FREQID                             Freq. ID to select.
SUBARRAY          0.0     1000.0   Subarray, 0=>1
DOCALIB          -1.0      101.0   > 0 calibrate data & weights
                                   > 99 do NOT calibrate weights
GAINUSE                            CL (or SN) table to apply
DOPOL            -1.0       10.0   If >0 correct polarization.
PDVER                              PD table to apply (DOPOL>0)
BLVER                              BL table to apply.
FLAGVER                            Flag table version
OUTFGVER          0.0              Output FG table version
DOBAND           -1.0       10.0   If >0 apply bandpass cal.
                                   Method used depends on value
                                   of DOBAND (see HELP file).
BPVER                              Bandpass table version
SMOOTH                             Smoothing function. See
                                   HELP SMOOTH for details.
STOKES                             Use 'I' to edit RR and LL
                                   combined, else task will set
BCHAN            0.0     8192.0    Low freq. channel in average
ECHAN            0.0     8192.0    High freq channel in average
BIF                                First IF displayed
EIF                                Last IF displayed
UVRANGE         0.                 Min & max baseline (klambda)
ANTENNAS                           List of antennas to be used
IN2NAME                            2nd UV file name
IN2CLASS                           2nd UV file class
IN2SEQ                             2nd UV file sequence
IN2DISK                            2nd UV file disk
DOHIST          -10.0       1.0    Record flags in history file
SOLINT            0.0              Data averaging time in mins
DETIME            0.0              Break interval (min)
DOWEIGHT          0.0              Rescale weights by DOWEIGHT
DOTWO            -1.0       1.0    True => do second observable
                                   plot of main baseline
EXPERT           -1.0       1.0    > 0 start in expert mode
CROWDED          -1.0       1.0    > 0 => allow plots with all
                                   polarizations and IFs
DO3COL           -1.0       2.0    > 0 => do CROWDED with
                                   multiple colors =2 always
REASON                             Initial reason string
ANTUSE            0.0      90.0    Initial displayed antennas
BADDISK           -1.0      1000.0 Disks to avoid for scratch.

HELP SECTION

EDITR
Type:  Task
Use:   To edit visibility data interactively using the TV graphics
       planes.  The visibility amplitude or phase or the amplitude of
       the visibility with a running average subtracted may be displayed
       in an edit window.  A second observable from the selected
       baseline is shown in a display adjacent to the edit window.
       Optionally, data in the primary observable for 1 to 10 other
       baselines to the selected antenna may be displayed over the same
       time range in areas above the second window.  The data are shown
       in a low-resolution, full time-range display or they may be shown
       with higher resolution by interactively selecting a "frame" or
       window of shorter time duration.  A second uv data set may also
       be displayed along with the first.  These data are not used for
       editing but may help you to select the data to be deleted.  A
       "normal" choice for the second data set would be the residuals
       after Cleaning or UVSUB.  A menu-like control interface is
       available to select the data, antenna, and time range to be
       edited and to select various forms of editing.  An "expert mode"
       allows you to enter single-letter menu selections from the
       keyboard (xterm) while this expert mode is enabled.

       EDITR creates a Flag Command file attached to the input UV data
       file.  If one already exists - due to a prior power failure or
       program failure - it will be used.  This is a bit dangerous and
       should be done only if the data selection adverbs have the values
       they had when the FC file was created.  When EDITR finishes, the
       FC table is translated into a standard Flag (FG) table.

       EDITR is for editing continuum data from one or more IFs.
       Multiple spectral channels may be averaged on input with the
       vector average used for display and editing; multiple IFs are
       kept separate.  The data may also be averaged over time as they
       are read into memory.  This is useful for improved
       signal-to-noise and to help squeeze the data into memory, but
       will cause the data flags to be less selective in time.  The
       program is more efficient if all data fit in memory, so EDITR
       will try to read all data into memory if it can.  Failing that it
       will try to read all data for one IF or all data for one antenna
       for all or one IF.  It will fail if this last case does not fit
       and you will need to use TIMERANGE or SOLINT to reduce the amount
       of data.
Adverbs:
  INNAME.....Input UV data file (name).       Standard defaults.
  INCLASS....Input UV data file (class).      Standard defaults.
  INSEQ......Input UV data file (seq. #).     0 => highest.
  INDISK.....Input UV data file disk drive #. 0 => any.
  SOURCES....Source list.  '*' = all; a "-" before a source name means
             all except ANY source named.
  QUAL.......Only sources with a source qualifier number in the SU table
             matching QUAL will be used if QUAL is not -1.
  CALCODE....Sources may be selected on the basis of the calibrator code
             given in the SU table.
                  '    ' => any calibrator code selected
                  '*   ' => any non blank code (cal. only)
                  '-CAL' => blank codes only (no calibrators)
                  anything else = calibrator code to select.
             NB: The CALCODE test is applied in addition to the other
             tests, i.e. SOURCS and QUAL, in the selection of sources to
             process.
  TIMERANG...Time range of the data to be copied. In order: Start day,
             hour, min. sec, end day, hour, min. sec. Days relative to
             reference date.
  SELBAND....Bandwidth of data to be selected. If more than one IF is
             present SELBAND is the width of the first IF required.
             Units = kHz. For data which contain multiple
             bandwidths/frequencies the task will insist that some form
             of selection be made by frequency or bandwidth.
  SELFREQ....Frequency of data to be selected. If more than one IF is
             present SELFREQ is the frequency of the first IF required.
             Units = MHz.
  FREQID.....Frequency identifier to select (you may determine which is
             applicable from the OPTYPE='SCAN' listing produced by
             LISTR). If either SELBAND or SELFREQ are set, their values
             override that of FREQID.  However, setting SELBAND and
             SELFREQ may result in an ambiguity.  In that case, the task
             will request that you use FREQID.
  SUBARRAY...Subarray number to copy. 0=>all.
  DOCALIB....If true (>0), calibrate the data using information in the
             specified Cal (CL) table for multi-source or SN table for
             single-source data.  Also calibrate the weights unless
             DOCALIB > 99 (use this for old non-physical weights).
  GAINUSE....Version number of the CL table to apply to multi-source
             files or the SN table for single-source files.
             0 => highest.
  DOPOL......If > 0.5 then correct data for instrumental polarization
             as represented in the AN or PD table.  This correction is
             only useful if PCAL has been run or feed polarization
             parameters have been otherwise obtained.  See HELP DOPOL
             for available correction modes: 1 is normal, 2 and 3 are
             for VLBI.  1-3 use a PD table if available; 6, 7, 8 are
             the same but use the AN (continuum solution) even if a PD
             table is present.
  PDVER......PD table to apply if PCAL was run with SPECTRAL true and
             0 < DOPOL < 6.  <= 0 => highest.
  BLVER......Version number of the baseline based calibration (BL) table
             to apply. <0 => apply no BL table, 0 => highest.
  FLAGVER....specifies the version of the flagging table to be applied
             to the data on input.     0 -> highest, -1 -> none.
  OUTFGVER...Flag table version to be used on output for both single-
             and multi-source data sets.  If OUTFGVER is <= 0 or
             greater than FGmax (the previously highest FG version
             number), then a new FG table will be created for the new
             flags with version FGmax+1.  This new table will also
             contain the flags applied on input (if any) from FG
             version FLAGVER.  If OUTFGVER specifies a pre-existing FG
             version, then the input flags are not copied even if
             OUTFGVER and FLAGVER are not equal.
  DOBAND.....If true (>0) then correct the data for the shape of the
             antenna bandpasses using the BP table specified by BPVER.
             The correction has five modes:
             (a) if DOBAND=1 all entries for an antenna in the table
             are averaged together before correcting the data.
             (b) if DOBAND=2 the entry nearest in time (including
             solution weights) is used to correct the data.
             (c) if DOBAND=3 the table entries are interpolated in
             time (using solution weights) and the data are then
             corrected.
             (d) if DOBAND=4 the entry nearest in time (ignoring
             solution weights) is used to correct the data.
             (e) if DOBAND=5 the table entries are interpolated in
             time (ignoring solution weights) and the data are then
             corrected.
  BPVER......Specifies the version of the BP table to be applied (if
             DOBAND > 0).  0 => highest numbered table.
  SMOOTH.....Specifies the type of spectral smoothing to be applied to
             a uv database . The default is not to apply any smoothing.
             The elements of SMOOTH are as follows:
             SMOOTH(1) = type of smoothing to apply: 0 => no smoothing
               To smooth before applying bandpass calibration
                 1 => Hanning, 2 => Gaussian, 3 => Boxcar, 4 => Sinc
               To smooth after applying bandpass calibration
                 5 => Hanning, 6 => Gaussian, 7 => Boxcar, 8 => Sinc
             SMOOTH(2) = the "diameter" of the function, i.e. width
               between first nulls of Hanning triangle and sinc
               function, FWHM of Gaussian, width of Boxcar. Defaults
               (if < 0.1) are 4, 2, 2 and 3 channels for SMOOTH(1) =
               1 - 4 and 5 - 8, resp.
             SMOOTH(3) = the diameter over which the convolving
               function has value - in channels.  Defaults: 1,3,1,4
               times SMOOTH(2) used when input SMOOTH(3) < net
               SMOOTH(2).
  STOKES.....Set STOKES='I' to force editing of RR and LL as one - this
             saves memory and will make the task faster.  Otherwise, the
             task sets STOKES to 'HALF' unless the first (or if present
             the 2nd) data set is already converted to I.  In that case,
             'I' is used for both.
  BCHAN......First channel number to include.  0 => 1.  Channels are
             averaged before being displayed.
  ECHAN......Highest channel number to to include in displayed average,
             0 => max
  BIF........The lowest numbered IF to include.  IFs may be edited
             separately in one run.   0 => 1.
  EIF........The highest numbered IF to include. 0 =>highest.  Note: not
             all data sets will have IFs.
  UVRANGE....Include data from UVRANGE(1) through UVRANGE(2)
             kilowavelengths. 0,0 => all.
  ANTENNAS...A list of antennas to be included (if all are > 0), data
             involving any other antenna is excluded.  If any one of the
             numbers is < 0, then ANTENNAS becomes a list of antennas to
             be excluded; data involving two antennas both not in
             ANTENNAS  are included.
  IN2NAME....2nd UV data file name.  This file will be displayed along
             with the first file, although only the first file may be
             used for editing.  All calibration is turned off for this
             second file.  BCHAN, ECHAN, BIF, and EIF are applied to the
             second file iff the second file has the same number of
             input channels and IFs as the first.  Otherwise, channels
             1 through ECHAN-BCHAN+1, IFs 1 through EIF-BIF+1 are
             included.  ' ' => no 2nd UV data set.
             This option is normally used for a "residual" uv data set
             set as that produced by IMAGR or UVSUB.
  IN2CLASS...2nd UV file class.  ' ' => no 2nd UV data set.
  IN2SEQ.....2nd UV data file sequence number. < 0 => do not
             use this option; = 0 => highest existing.
  IN2DISK....2nd UV data file disk number. = 0 => any.
  DOHIST.....> 0 => record task execution and flagging info in the
             history file (this can be a lot!).  <= 0.0 means to omit
             the flagging info and <= -9.5 means to omit the execution
             information as well.
  SOLINT.....Data are averaged in time over SOLINT minutes to produce
             better signal to noise and to reduce memory requirements.
             0 => 1/6000(0.01 s).  If you want averaging, set this
             number appropriately.  Editing times are offset by
             SOLINT/2 which may cause confusion if no averaging occurs.
             When you do this, you must set a DETIME value which
             correctly represents your data; the default can put a gap
             between every sample which is costly in memory and data
             access.
  DETIME.....Samples more than DETIME (minutes) from the previous will
             be considered to imply a break in the time sequence and
             will be assigned a time interval after a gap of 1 interval
             or 2 intervals if the sample is more than 2 * DETIME later.
             < SOLINT => MAX (2, 5*SOLINT).  DETIME is used as the
             initial estimate of the scan length as well - this may be
             changed interactively.
  DOWEIGHT...The display of error bars (restricted to amplitudes)
             depends on the data weights being 1/(sigma**2) in 1
             (Jy**2).  Set DOWEIGHT to get the data weights into this
             scale, multiplying the input weights by DOWEIGHT.  0 -> 1.
  DOTWO......> 0 (true) means to do the secondary plot of a second
             observable (phase, amplitude, diff amplitude) from the
             primary baseline.  <= 0 means to plot only the primary
             observable used for the editing.  True is highly
             recommended.
  EXPERT.....> 0 => the task begins in "expert mode" in which commands
             are entered with single characters at the keyboard rather
             than by TV menu selection.  You can switch in and out of
             expert mode interactively after the task begins without
             regard for the value of EXPERT.  If the task begins in
             EXPRT mode, it starts with the amplitudes and difference
             amplitudesplotted from 0 to maximum and phases from -180
             to 180 and with the ALL IF and ALL POL flags =NOT.CROWDED
             rather than false.  These choices may be changed
             interactively.
  CROWDED....If true (> 0), the task will be allowed to plot and edit
             all IFs and/or all polarizations at once.  Otherwise,
             only one polarization and one IF are plotted at a time
             and much of the editing is based only on the values of
             that polarization/IF.
  DO3COL.....If CROWDED > 0 and DO3COL > 0, use 3 grey-scale image
             planes to plot the data in colors so as to differentiate
             between IFs and polarizations.  When one IF and
             polarization is plotted, the graphics plane is used
             unless DO3COL > 1.5.
  REASON.....The initial reason for flagging recorded in the FG table.
             ' ' => task name, date and time.  This can be changed
             interactively.
  ANTUSE.....Lists the antennas to appear in the initial display:
             baseline ANTUSE(1)-ANTUSE(2) is the initial edit baseline
             and ANTUSE(1)-ANTUSE(3) through ANTUSE(1)-ANTUSE(12) are
             the comparison baselines.  The default is equivalent to
             ANTUSE=1,2,3,4 (or whatever are the 4 lowest numbered
             antennas).
  BADDISK....This array contains the numbers of disks on which it is
             desired that scratch files not be located.

EXPLAIN SECTION


     EDITR is a TV graphic editor for uv data using the uv data
themselves and optionally a second data set (e.g. residuals).  It works
with the XAS-TV display graphics planes (7 of them) to allow you to flag
uv data based on their values.  It does not change the input data set,
but will write a flag table.

     EDITR averages spectral channels and over a specified time interval
as it reads the data set(s).  It attempts to read the entire data set
into the pseudo-AP memory when if starts up.  If it cannot fit all the
data, it attempts to read just one IF at a time and/or all baselines to
one antenna at a time.  In that case, when you switch IFs or main
antennas, EDITR has to read in the next IF or set of baselines.  EDITR
will tell you as it starts whether "All data will reside in memory" or
various other combinations.  Judicious choices of SOLINT and TIMERANGE
can help the task to read all selected data and thus to be more
efficient

     There are 6 parts to EDITR's display:
(1) A menu of operations displayed in two columns, one each at the left
and right sides of the screen.  When the menu is displayed, move the
cursor to the desired item and press buttons A, B, or C.  To get on-line
help in the message window about a given option, move the cursor to the
desired menu item and press button D.
(2) A plot at the bottom of the screen in a bright color (usually) of
the data which may be actively edited at present.  It is of the chosen
type for the selected baseline, polarization(s), and IF(s) and is
limited in time range by the current frame (which can be all or a
portion of the total time range).  Flagged data are shown in a
different color.  The time range of the frame may be made small to
expand the time axis, but may also be made so large as to cause
serious crowding of the plotted data points.  (Increase your XAS
window width to increase the plot scale.)
(3) A plot above the edit area plot in the same bright color of the data
from the selected baseline, polarization(s), and IF(s).  This plot is
in a second observable (e.g. if amplitude is in the edit plot, phase
is often the second observable).  Data in this second area may not be
used for editing but should be helpful in choosing which data to
delete in the edit area.  Flagged data are shown in a different color.
This plot may be suppressed by adverb DOTWO.
(4) 0-10 plots of data of the current data type, polarization(s), and
IF(s) for a list of 0-10 other baselines to the main antenna are shown
above the second plot.  They are shown for comparison using another
color, while flagged data are shown in a different color.
(5) If a second uv data set was specified, its data will be shown in
another color in each of the windows (2, 3, 4) above.
(6) Several text areas also appear including (a) the start and end times
for the current frame's time axis, (b) the selected data type, IF, and
polarization at the bottom of the screen, (c) the antenna shown in each
plot at the top right of each plot, (d) the current all-IF,
all-polarization, and all-antenna flags, (e) the y-axis tick values on
each of the frame plots, and (f) while interactively setting time and/or
value ranges, the time and/or value to which you are currently pointing
and the associated source name.

     You may change the size of the XAS window at any time.  EDITR will
not allow it to become too small, but will adjust its display for all
reasonable sizes.

     The left-hand menu can contain

| FLAG TIME       |  To delete one time at a time.
| FLAG TIME RANGE |  To delete one or more time ranges.
| FLAG BELOW      |  To delete all displayed times with data below a
                        cutoff value.
| FLAG ABOVE      |  To delete all displayed times with data above a
                        cutoff value.
| FLAG AREA       |  To delete one or more areas in the data-value -
                        time plane.
| FLAG POINT      |  To delete one sample at a time using both
                        horizontal and vertical cursor position.
| FLAG QUICKLY    |  To delete samples using only mouse clicks
| ENTER AMPL RNG  |  To select the display range for amplitude plots:
                        0 -1 for 0 to maximum, 0 0 for min to max
| ENTER PHASE RNG |  To select the display range for phase plots.
| ENTER DAMP RNG  |  To select the display range for plots of the
                        amplitude of the visibility minus a running
                        vector average visibility.
| PLOT ERROR BARS |  To plot error bars based on data weights
| SET SCAN LENGTH |  To set the averaging time used to determine the
                        running average in seconds.
| LIST FLAGS      |  To list all flags now in the Flag Command table.
| UNDO FLAGS      |  To undo one of the flag operations in the FC table
| REDO FLAGS      |  To reapply all remaining flags after one or more
                     have been undone (see note below)
| SET REASON      |  To set the 24-character "reason" string to be put
                        in the uv-data flag table
| USE EXPERT MODE |  To control the task from the keyboard instead of
                        the menu.
| HOLD TV LOAD    |  To stop updating the TV display with every change
                     of parameter; change several, then select
| DO TV LOAD      |  To update the TV display now and with each change
                     of display parameter.
| REPLOT          |  To do the current plot over again, recomputing
                     the differences from the running mean if
                     appropriate.
| EXIT            |  To exit EDITR, moving the FC table to a uv-data FG
                     table
| ABORT           |  To exit EDITR, deleting the FC table


     The right-hand menu can contain

| NEXT POL/IF     |  To switch to viewing the next correlator,
                        switching to the other polarization and, if
                        needed, incrementing the IF.
| SWITCH POLARIZ  |  To switch to viewing and editing the other
                        polarization (can cycle through all).
| SWITCH ALL POL  |  To switch functions from applying to one
                        polarization to applying to both polarizations
                        or vice versa.
| ENTER IF        |  To select which IF is viewed and edited.  This
                        can force a read of data if all IFs did not fit
                        in memory.  0 -> all.
| SWITCH ALL IF   |  To switch functions from applying to one IF, to
                        applying to a range of IFs, or to applying to
                        all IFs (in sequence).
| SWITCH ALL TIME |  To switch FLAG ABOVE and FLAG BELOW between all
                        times and the time range of the frame
| ROTATE ALL ANT  |  To rotate functions from applying to (a) one
                        baseline, (b) all baselines to the main antenna,
                        and (c) all baselines.
| SWITCH ALL SOURC|  To switch between flagging the current source and
                        all sources.
| ENTER ANTENNA   |  To select the main antenna, baselines to which are
                        displayed on the screen.
| ENTER OTHER ANT |  To select up to 11 other antennas to define the
                        baselines to be displayed; enter 10 numbers, 0's
                        are then ignored (to plot 5 enter the 5 plus 6
                        0's).  The first one is used for the edit area.
| NEXT BASELINE   |  To rotate the list of other antennas, selecting
                        the next one for the edit area.
| NEXT ANTENNA    |  To select a new main antenna, one higher than the
                        current main antenna.  The "others" MAY also
                        be adjusted.
| PLOT ALL TIMES  |  To display all data for the selected baselines.
| SELECT FRAME    |  To select a window into the current data
                        interactively.
| NEXT FRAME      |  To select the next time-range window of the same
                        size as the current frame.
| PREVIOUS FRAME  |  To select the previous time-range window of the
                        same size as the current frame.
| SHOW AMPLITUDE  |  To display and edit amplitudes.
| SHOW PHASE      |  To display and edit phases.
| SHOW DIFF AMPL  |  To display and edit the amplitudes of the vector
                        difference between the sample and its running
                        mean
| SHOW ALSO AMPL  |  To display amplitudes of the edit baseline for
                        reference with the phase or difference
                        amplitude edit window.
| SHOW ALSO PHASE |  To display phases of the edit baseline for
                        reference with the amplitude or difference
                        amplitude edit window.
| SHOW ALSO DAMP  |  To display difference amplitudes of the edit
                        baseline for reference with the phase or
                        amplitude edit window.
| TV ZOOM         |  To alter the display zoom used while in the flag
                        functions.
| OFF ZOOM        |  To turn off any zooming.
| 2ND UV OFF      |  To disable the display of the 2nd uv data set.
| 2ND UV ON       |  To enable the display of the 2nd uv data set.


     The menus will not show all of these options every time.  The HOLD
TV LOAD option is shown until invoked, and then is replaced with the DO
TV LOAD.  When that is invoked, the HOLD TV LOAD option reappears. The
SWITCH POLARIZ and SWITCH ALL POL options appear only if there are two
polarizations in the data.  The ENTER IF option appears only if there is
more than one IF in the data and the SWITCH ALL IF option appears only
if there is more than one IF and all IFs fit in the program memory.
Only one of the three SHOW ALSO choices appears at any one time.

     Plots of the difference between the visibility and its running mean
can be particularly sensitive to short term disturbances while ignoring
slow changes due to gradually changing source structure and the like.
The running mean is not carried between sources and, as a result, is not
normally carried across scan boundaries.

     Note that value-dependent flagging (FLAG BELOW, ABOVE, AREA) use
the values currently plotted to make a list of value-independent flag
commands (i.e., a single time for the specified antennas, IFs,
polarizations, etc.).  When a value-dependent FLAG operation is undone
(UNDO FLAGS) or redone (REDO FLAGS), it is these value-independent flags
which are undone or redone.  You may have to undo more commands and then
repeat FLAG commands to get the results you could have gotten by doing
the now desired value-dependent command in the first place.  You need
also to be careful with the ROTATE ALL ANT setting with these
value-dependent commands.  If one baseline is set, then the commands
only apply to the current baseline.  If one antenna is set, the commands
apply to all baselines to the current main antenna, while if all
antennas is set, the commands apply to all baselines.  The first two set
a clip level, below or above which data are deleted, based on the value
of the observable in each baseline independently.  The FLAG AREA
command, however, only looks at the values of the observable in the main
edit baseline and flags those samples from all applicable baselines.

     Be careful when choosing EXIT versus ABORT.  The former applies the
flag commands to a flag table attached to the input uv data, the latter
causes the flag commands to disappear without a trace.  After EXIT, of
course, one may use, edit, or ignore the output flag (FG) table.  For
single-source files, it may be necessary to run SPLIT to apply the FG
table to the data since only some tasks know how to apply FG tables
(those with FLAGVER as an adverb).

     The colors used by EDITR are those of the various graphics planes
when it begins to run.  You may change them with the AIPS verb GWRITE to
more desirable colors.  The planes are:
   Plane     Default RGB      Use
     1     1.00  1.00  0.00   Main editing and secondary windows
     2     0.06  1.00  0.00   Comparison baseline data windows
     3     1.00  0.67  1.00   Menu highlight
     4     0.00  1.00  1.00   Edit and frame window boundaries
     5     1.00  0.18  0.18   Flagged data in all windows
     6     0.60  0.60  1.00   Menu foreground
     7     1.00  0.80  0.40   Second uv data set if present
You may wish to change the colors to ones that you can see better.
When CROWDED and DO3COL are invoked together, TV channels 14-16 are
used for a 3-color display to help you see which IF/polarization is
which.  The colors range from red to blue starting with IF BIF,
polarization 1, then polarization 2, then IF 2 polarization 1, and so
on.  When you select a single IF and polarization, graphics plane 1 is
used unless you set DO3COL > 1.5.  In that case each correlation is
plotted in its unique color whether in a single display or a crowded
one.  When displaying one IF and two polarizations, the colors are
chosen so that polarization 1 appears in a red/orange color and
polarization 2 in a green/blue color.

     In "expert" mode, you are prompted with a set of 4-character codes.
You type in the letter within that code that is shown in upper case
(left-justified with a carriage return) to get the desired function.
The expert functions allowed are

      Code  Prompt  Full menu OP name
         T   Time   FLAG TIME
         R   Rang   FLAG TIME RANGE
         B   Belo   FLAG BELOW
         A   Abov   FLAG ABOVE
         E   arEa   FLAG AREA
         O   pOin   FLAG POINT
         Q   Quik   FLAG QUICKLY
         L   List   LIST FLAGS
         U   Undo   UNDO FLAGS
         S   baSl   NEXT BASELINE
         C   nCor   NEXT POL/IF
         N   Nant   NEXT ANTENNA
         F   Fram   SELECT FRAME
         M   aMpl   SHOW AMPLITUDE
         P   Phas   SHOW PHASE
         D   aDif   SHOW DIFF AMPL
         X   eXit   EXIT EXPERT MODE
         H   Help   THIS HELP LIST

although some may be suppressed depending on what is currently
displayed.


AIPS