AIPS HELP file for VPLOT in 31DEC24
As of Fri Apr 26 9:53:38 2024
VPLOT: Plots data from a u,v data base, model from a CC file
INPUTS
USERID -32000.0 32000.0 File owner number - ignored
INNAME Input UV file name (name)
INCLASS Input UV file name (class)
INSEQ 0.0 9999.0 Input UV file name (seq. #)
INDISK 0.0 3.0 Input UV file disk unit #
IN2NAME Input CC file name (name)
IN2CLASS Input CC file name (class)
IN2SEQ 0.0 9999.0 Input CC file name (seq. #)
IN2DISK 0.0 3.0 Input CC file disk unit #
IN2VERS 0.0 46655.0 Input CC file version #
NCOMP # comps to use for model.
1 value per field
total 200000 CCs maximum
FLUX Lowest CC component used.
NMAPS -4096.0 4096.0 # clean maps (fields).
0 => no model
>0 => model at samples
<0 => model smoothly
Data selection:
SOURCES Source list
QUAL -10.0 Source qualifier -1=>all
CALCODE Calibrator code ' '=>all
SELBAND Bandwidth to select (kHz)
SELFREQ Frequency to select (MHz)
FREQID Freq. ID to select.
BCHAN 0.0 4096.0 Lowest channel number 0=>1
ECHAN 0.0 4096.0 Highest channel number
0 => high if AVGCHAN
0 => BCHAN otherwise
AVGCHAN -1.0 1.0 > 0 => average BCHAN-ECHAN
BIF 0.0 100.0 Lowest IF number 0=>1
EIF 0.0 100.0 Highest IF number 0=>high
AVGIF -1.0 1.0 > 0 => average IFs
CROWDED -1.0 3.0 Plot chans/IFs together or
separately? 0 separate,
3 all together, 1 & 2 partly
DO3COLOR -1.0 1.0 Plot separate IFs in separate
colors.
XINC 0.0 9999.0 Plot every XINC'th visibility
0 => 1
UVRANGE 0.0 Range of projected spacings
(thousands of wavelengths)
TIMERANG Time: start day,hr,min,sec
stop day,hr,min,sec.
STOKES Stokes' parameters
ANTENNAS Antennas to be plotted
BASELINE Baselines with ANTENNAS
See explanation.
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
See explanation.
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
SUBARRAY Subarray number 0=>1.
-1 => all, but beware!
DOEBAR If > 0, plot error bars,
else don't
SOLINT Time over which to average
data before plotting (mins)
=0 => no averaging
>0 SOLINT=MIN(SOLINT, SCAN)
<0 SOLINT=ABS(SOLINT)
average through scans
OPTYPE 'AUTO' => autocorrelation
else =>crosscorrelation
OPCODE Type of plot:
'IFRA' => ratio BIF and EIF
else => plot requested IF
APARM Control parameters
1 : > 0 => edit bad
amplitude points.
BPARM(2)=0, or 1
= 0 => do not edit
bad amplitude points.
Number of averaged points
for each baseline has to
be more than 10.
2 : number of sigmas outside
of which bad points are
clipped (See HELP); 0=>3.
3 : > 0 plot min/max range
with average
= 0 do not plot min/max
lines
4 : = 0 min/max over selected
IFs after averaging
selected CHs
> 0 min/max over all
selected CH/IFs
5 : > 0 scalar average
= 0 vector average
6 : used with APARM(1)>0
>0 flag the bad points
for all channels
=0 flag the bad points
only for the selected
channels
7 : est total plot points
8 : > 0 mark scan boundaries
BPARM Control parameters
1 : X-axis type code 0 -> 12
2 : Y-axis type code 0 -> 1
<0 => both AMP & PHASE
1=> amplitude (Jy)
2=> phase (degrees)
3=> uv dist. (klambda)
4=> uv p.a. (deg N->E)
5=> time (IAT days)
6=> u (klambda)
7=> v (klambda)
8=> w (klambda)
9=> Re(Vis) (Jy)
10=> Im(Vis) (Jy)
11=> time (GST)
12=> time (IAT hours)
13=> source number
14=> freqid
15=> integration time
16=> weight
17=> rms (SOLINT > 0)
18=> HA (hours)
19=> elevation (deg)
20=> parallactic angle
21=> azimuth (deg)
22=> log(amplitude)
3 : >0.0 => fixed scale
<0.0 => fixed range
0.0 => sep. scales
4 : Xmin (fixed scale)
5 : Xmax (fixed scale)
6 : Ymin (fixed scale)
7 : Ymax (fixed scale)
8 : PHmin (fixed scale)
9 : PHmax (fixed scale)
10: > 0 -> plot models for
baselines with no data
ALIAS Antenna alias selection
If ALIAS(1) is non-zero, any
antennas matching ALIAS(2-30)
are treated as if they were
actually ALIAS(1)
REFANT 0.0 90.0 > 0 -> use REFANT for hour
angle, elevation, et al.
NPLOTS Max number of plots per page.
0 => 3; If bparm(2)<0 =>
Max number of pairs of plots.
POLPLOT Option to display various
ratios of polarizations:
see help for allowed values
other = plot data directly
SYMBOL 0.0 24.0 Symbol to use when plotting.
0 => X (FACTOR >= 0)
=> none (FACTOR < 0)
1 - 23, standard types
FACTOR Scale symbol by FACTOR
< 0 => connect with lines
LTYPE -410.0 410.0 Type of labeling: 1 border,
2 no ticks, 3 - 6 standard,
7 - 10 only tick labels
<0 -> no date/time
DOTV -1.0 1.0 > 0 Do plot on the TV, else
make a plot file
GRCHAN 0.0 8.0 Graphics channel 0 => 1.
XYRATIO 0.0 X/Y ratio 0 -> fit TV or 1 PL
BADDISK Disks to avoid for scratch
HELP SECTION
VPLOT
Type: Task
Use: Plots data from a u,v data base making a plot file. Also, if a
valid CLEAN map is specified the model values wlll be plotted.
Plotting is done one baseline per plot with the number of plots
per page specified by NPLOTS. The plots are written one page
per plot file so in general several plot files will be created.
Model types recognized are: points, elliptical gaussians and
uniform spheres. This task is the fast version of VBPLT. The
option of plotting amplitude and phase together has been added.
VPLOT can handle images made with the DO3DIMAG option of IMAGR.
It recognizes them automatically and does the proper CC model
computation. It also can handle multi-scale images; set
NMAPS = NFIELD * NGAUSS.
Adverbs:
USERID.....Input file user number. Ignored
INNAME.....Input UV file name (name) Standard defaults.
INCLASS....Input UV file name (class) Standard defaults.
INSEQ......Input UV file name (seq. #) 0 => highest.
INDISK.....Disk drive # of input UV file. 0 => any.
IN2NAME....Name of desired CLEAN components to be used.
If this file is not found no model will be plotted
Uses Standard defaults.
IN2CLASS...Class of CLEAN map. Standard defaults.
IN2SEQ.....Sequence number of CLEAN map. 0 => highest.
IN2DISK....Disk number of CLEAN map. 0 => any.
IN2VERS....CLEAN component file version (CC tables) 0 => highest.
The same version number is used for the all selected
image files. Use task TACOP to provide the same numbers
for desired CC tables.
For a multi-source file, the flux of the clean components
selected for the model are summed and scaled to the source
flux found in the SU table. If that flux is zero, no
scaling is done.
NCOMP......Number of Clean components to use for the model, one
value per field. If all values are zero, then all
components in all fields are used. If any value is not
zero, then abs(NCOMP(i)) (or fewer depending on FLUX and
negativity) components are used for field i, even if
NCOMP(i) is zero. If any of the NCOMP is less than 0,
then components are only used in each field i up to
abs(NCOMP(i)), FLUX, or the first negative whichever
comes first. If abs(NCOMP(i)) is greater than the number
of components in field i, the actual number is used. For
example
NCOMP = -1,0
says to use one component from field one unless it is
negative or < FLUX and no components from any other
field. This would usually not be desirable.
NCOMP = -1000000
says to use all components from each field up to the
first negative in that field.
NCOMP = -200 100 23 0 300 5
says to use no more than 200 components from field 1, 100
from field 2, 23 from field 3, 300 from field 5, 5 from
field 6 and none from any other field. Fewer are used if
a negative is encountered or the components go below
FLUX. *** This option is limited to the first 200000
Clean components encountered. ***
FLUX.......Only components > FLUX in absolute value are used in the
model.
NMAPS......Number of image files to use for model. For multi-scale
models, set NMAPS = NFIELD * NGAUSS to include the Clean
components of the extended resolutions. If more than one
file is to be used, the NAME, CLASS, DISK and SEQ of the
subsequent image files will be the same as the first file
except that the LAST 3 or 4 characters of the CLASS will
be an increasing sequence above that in IN2CLASS. Thus,
if INCLASS='ICL005', classes 'ICL005' through 'ICLnnn'
or 'ICnnnn', where nnn = 5 + NMAPS - 1 will be used. Old
names (in which the 4'th character is not a number) are
also supported: the last two characters are '01' through
'E7' for fields 2 through 512. In old names, the highest
field number allowed is 512; in new names it is 4096.
= 0 => do not plot a model
> 0 => plot the model at each data sample. In this mode,
the u,v,w are known from the data sample, but the
sampling for each baseline may be coarse and
irregular.
< 0 => plot a model at 200 regularly sampled points for
each baseline. In this mode, the u,v,w's are
computed from the times and antenna locations and
may have subtle (or not so subtle) complications
(with precession, u-v rotation, times) causing the
plotted model to fail to match the plotted data.
SOURCES....Source list. If the data is a multi-source file
VPLOT will plot the visibility for the first
source specified. If the data is a single
source file no source name need be specified.
QUAL.......Only sources with a source qualifier number in the
SU table matching QUAL will be used if QUAL is not
-1.
CALCODE....Calibrators may be selected on the basis of the
calibrator code:
' ' => 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. CALSOUR and QUAL, in the
selection of sources for which to determine
solutions.
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, 0=> all
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, 0=> all
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 overide that of FREQID,
however setting SELBAND and SELFREQ may occasionally
result in an ambiguity, in which case the task will
request that you use FREQID.
BCHAN......Start channel. 0 => 1
ECHAN......End channel. If AVGCHAN <=0, 0 => BCHAN (NB: this is
a non-standard default). If AVGCHAN > 0, ECHAN < BCHAN
=> highest.
AVGCHAN....> 0 => Average the spectral channels BCHAN through ECHAN
before plotting.
<=0 => Plot the channels separately
BIF........Start IF number to plot. 0 => 1
EIF........End IF number to plot. 0 => highest
If OPCODE = 'IFRA' will plot ratio of visibilities
at BIF and EIF.
AVGIF......> 0 => IFs BIF through EIF will be averaged before
plotting, otherwise they will be plotted separately.
CROWDED....<= 0 => Plot IFs and spectral channels individually
multiple polarizations, if requested, do appear
in the same panel.
= 1 => Plot spectral channels together in one panel but
separate panels for separate IFs
= 2 => Plot IFs together in one panel but separate
panels for each spectral channel
= 3 => Plot spectral channels and IFs together in one
panel (per baseline)
DO3COLOR..> 0 => plot the separate polarizations, spectral channels,
and IFs in different colors, otherwise they are done in
the same color. Done only to differentiate things plotted
in the same panel. The scheme is:
COLOR = 0
DO POL = 1,Npol
DO IF = 1,Nif
DO CHAN = 1,Nchan
set and use COLOR
COLOR = COLOR + DeltaColor
END DO CHAN
END DO IF
END DO POL
where COLOR=0 is pure red, DeltaColor is set so that the
last value of COLOR is 1 which is pure blue. Npol is the
number of requested polarizations, Nif is the number of
IFs plotted in the panel (BIF to EIF if CROWDED > 1, else
1), and Nchan is the number of spectral channels plotted
in the panel (1 unless AVGCHAN<=0 and CROWDED is 1 or 3).
Thus, if there are 4 IFs, one spectral channel (average),
and one polarization, the plot will be of red, yellow,
cyan, and blue for IFs 1 through 4, resp. If there are 2
IFs and 2 polarizations (RR and LL say), then red is RR
in IF 1, yellow is RR in IF 2, cyan is LL in IF 1, and
blue is LL in IF 2. Note that the blue is plotted after
the blue and so may overlap and obscure the red.
XINC.......Plot every XINC'th visibility
which might be plotted. 0 => 1
UVRANGE....Range (min, max) of projected baselines to include
0,0 => all baselines
TIMERANG...The specified time range.
1 = Start IAT day (day 0 = first day in data base)
2 = Start IAT hour
3 = Start IAT minute
4 = Start IAT second
5 = Stop IAT day (day 0 = first day in data base)
6 = Stop IAT hour
7 = Stop IAT minute
8 = Stop IAT second
stop IAT = 0 => beginning
stop IAT = 0 => end.
of time.
Note that multi-subarray data are separated by 5 days for each
subsequent subarray if the data are DBCON's output.
VPLOT does not remove this time shift starting May 1, 2001.
So pay attention on this fact selecting the TIMERANG.
STOKES.....Specifies the stokes type to be plotted - usually only 1
Recognized values are 'I', 'Q', 'U', 'V', ' ' => 'I'
'RR', 'LL', 'LR', 'RL', 'VV', 'HH', 'VH', 'HV'
'RRLL', 'VVHH', 'RLLR', 'VHHV', 'IV', 'HALF', 'FULL'
will plot 2 polarizations at once
'IQU' plots 3 and 'IQUV' plots 4 at once
ANTENNAS...A list of the antennas to be plotted.
If OPTYPE = 'auto' then the specified channels and/or IFs
from the self-spectra of the selected ANTENNAS are plotted
(and BASELINE should be 0 or the same as ANTENNAS).
BASELINE...Baselines between antennas named in ANTENNAS and those
named in BASELINE are selected.. There are four possible
combinations of ANTENNAS and BASELINE:
1. ANTENNAS = 0; BASELINE = 0.
All possible baselines are selected.
2. ANTENNAS <>0; BASELINE = 0.
a)All ANTENNAS > 0
Baselines including an antenna in the ANTENNAS list
are selected;
b)Some ANTENNAS < 0
All baselines NOT including an antenna in the ANTENNAS
list are selected;
3. ANTENNAS = 0; BASELINE <> 0.
a)All BASELINE > 0
Baselines including an antenna in the BASELINE list
are selected;
b)Some BASELINE < 0
All baselines NOT including an antenna in the BASELINE
list are selected;
4. ANTENNAS <> 0; BASELINE <> 0.
a)All ANTENNAS>0 and all BASELINE>0
Baselines between antennas named in ANTENNAS and those
named in BASELINE are selected.
b)Some ANTENNAS<0 .OR. some BASELINE<0
Baselines between antennas named in ANTENNAS and
those named in BASELINE are DE-selected, all others
are selected.
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
multisource files or the SN table for single
source files. 0 => highest.
DOPOL......If > 0 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 appply. <0 => apply no BL table,
0 => highest.
FLAGVER....specifies the version of the flagging table to be
applied.
0 => highest numbered table.
<0 => no flagging to be applied.
If APARM(1)>0 then
if FLAGVER>0 => the specified table is copied to
the next highest version and recognized bad points
are added to this table
if FLAGVER=0 => the highest numbered table is copied
to the next highest version and recognized bad
points are added to this table
if FLAGVER<0 => Recognized bad points
are recorded in a new FG table
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
0 => highest numbered table.
<0 => no bandpass correction to be applied.
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).
SUBARRAY...The subarray number desired. 0=> 1.
To have all subarrays plotted, give -1. Be aware that the
station names and model plotted will be for subarray 1
only. Elevations, hour angles, parallactic angles, and
azimuths are also computed wrt SUBARRAY (or 1 if = 0).
DOEBAR.....If = 0 => do not plot error bars on data
if = 1 => do plot error bars.
SOLINT.....Time over which to pre-average data before plotting
(minutes). =0 => no pre-averaging.
If SOLINT<0, then SOLINT = ABS(SOLINT) and averaging will
cross source boundaries. Otherwise, it does not.
All axis types are now available.
OPTYPE.....Specify whether the user wishes to plot data from
the cross-power spectra (OPTYPE is anything but 'AUTO')
or the self-spectra (OPTYPE='AUTO')
OPCODE.....Type of plot:
'IFRA' => ratio between IF's (BIF and EIF)
else => will plot each requested IF
APARM......Control parameters:
1 : > 0 => edit bad amplitude points during the pre-average and
write FG entries to delete them.
If autocorrelation is selected (OPTYPE='AUTO') then
all baselines with selected antennas are flagged
for the bad amplitudes.
= 0 => do not edit bad amplitude points
2 : number of sigma (rms) used in deciding if a point should be
flagged.
If APARM(2)=0 then APARM(2)=3
Regime APARM(1)>0 is used in an average mode (in time,
IFs, Channels) and can be useful for the editing of points
with large amplitude deviation.
Regime APARM(1) works only with plotting of amplitude.
BPARM(2)=0, or 1.
The amplitude of each individual point in the average
interval is compared with the mean value.
The rms is estimated for the solution interval
simultaneously.
!!Number of averaged points for each baseline has to be
!! more than 10.
If the deviation of the amplitude from the mean is
larger than the specified multiple of the rms then that
point is marked in a new flag table.
The new flag table is a copy of the specified flag
table. If FLAGVER=0 the highest numbered flag table is
copied and added to.
If a flag table does not exist or FLAGVER<0, a new flag
table is created. See FLAGVER section above..
Plots are not generated in the bad point recognition mode.
3 : > 0 plot a vertical line that specifies the minimum and
maximum of the amplitudes (or phase or real or image)
found in the domain of averaging.
The minimum and maximum values of the average are stored
for each baseline as well as mean values.
Vertical lines with lower and upper limits corresponding
to the minima and maxima are plotted together with mean
values. This mode is useful for recognition of the points
with a large deviation of amplitude or phase. Such points
are usually hidden in averaging.
= 0 do not plot min/max line when averaging and displaying
amplitudes.
4: = 0 Min/Max for the vertical line is found over
all points in time, IFs, Channels domain.
> 0 Min/Max for the vertical line is found over
points in time, IFs domain after averaging selected channels.
5 : > 0 scalar average used when SOLINT not 0
= 0 vector average
6 : used with APARM(1)>0.
If APARM(6)=0 flag the bad points for the selected channels.
If APARM(6)>0 flag the bad points for all channels.
The option APARM(6)>0 is useful in self calibration, of
a spectral line project when one channel is selected for
self calibration. This channel is edited but the editing
result should be applied to all channels
7 : Estimated total number of samples: 0 -> number of vis in the
data set which can be way too much if averaging or various
data selections are being made. This is used to set the size
of dynamic memory created and can limit the number of points
plotted.
8 : > 0 mark scan boundaries, >= 2 divider crosses whole plot
only when BPARM(1) = 5 or 12
BPARM......Control parameters:
1 = type of X-axis (where 1 = amplitude, 2 = phase, 3 = uv
distance, 4 = uv p.a. (CCW from u-axis), 5 = time (IAT)
6 = u, 7 = v, 8 = w, 9 = real part, 10 = imaginary part
11 = time (GST), 12 = time (IAT hms), 13 = source no.,
14 = freqid, 15 = int. time, 16 = weight, 17 = rms
(can only do if SOLINT > 0), 18 = hour angle (hours),
19 = elevation (degrees), 20 = parallactic angle (deg),
21 = azimuth (deg), 22 = log10(amplitude). 0 => 12
2 = type of Y-axis (as above). 0 => 1;
If <0 => Both Amplitude and phase are plotted.
-22 => log10(amplitude) and phase are plotted
3 = if greater than zero, use BPARM(4) - BPARM(8) as the
ranges of the axes. If less than zero, use the BPARMs
to limit the range of the axes, but self-scale the axes
within that range. If 0.0, scale the Y axis separately
for each baseline.
4 = Minimum of X-axis. See note below on units.
5 = Maximum of X-axis (if = BPARM(4) do self-scale in X).
6 = Minimum of Y-axis. See note below on units.
7 = Maximum of Y-axis (if = BPARM(6) do self-scale in Y).
8 = PHmin (fixed scale) is used for plotting both Amp and
phase together (BPARM(2) <0)
9 = PHmax (fixed scale) is used for plotting both Amp and
phase together (BPARM(2) <0)
Note that phase is initially computed in the range -180 to
180 degrees, but will be plotted in the range 0 to 360 if
specified as such. In self-scaled phase plots, the plot with
the smaller total range of those two possibilities is used.
Values > 360 or < -180 are not available.
10= Control of plotting for baselines with no data samples:
> 0 => plot such baselines if a model is being plotted
<= 0 => don't plot them - such baselines are never
plotted if there is not a model being plotted.
Units to use in BPARM(4) - BPARM(7):
axis type = 1, 9, 10 Jy
2, 4 Degrees
3, 6, 7, 8 Kilo wavelengths
5, 12 Days from start of observation
11 Hours
The axes will be labeled in appropriately scaled units, with axis
types 11 and 12 expressed in sexagesimal (hours, minutes, seconds as
needed). NOTE: two models will be plotted if the x axis type is 3,
6, 7, or 8 (uv distance, u, v, w) since the x axis value determines
the baseline only with an ambiguity. Models are plotted only if the
y-axis type is 1, 2, 9, or 10 and the x-axis type is NOT 1, 2, 9, or
10 (and if NITER > 0 and there is an appropriate CC file).
ALIAS.......Any antenna that appears in ALIAS(2...30) will be treated
as if it was actually the antenna specified in ALIAS(1).
e.g. ALIAS = 3 7 9 1 0 results in antennas 1,3, 7 and 9
being treated as if they were actually one antenna [which
is labelled antenna 3].
REFANT......Hour angle, elevation, parallactic angle, and azimuth
are actually antenna parameters not baseline parameters.
If REFANT > 0, these plot parameters will be those
evaluated at antenna REFANT.
If REFANT = 0, these parameters are
evaluated at each antenna of an antenna pair and averaged
for plotting purposes.
NPLOTS......Max number of plots per page. 0 => 3. If AMP and
PHASE are plotted together (BPARM(2) < 0), NPLOTS
equals max. number of pairs of plots per page.
POLPLOT.....An option to display the ratio of various correlated
values. Allowed combinations are: 'RL/RR', 'RL/LL',
'LR/RR', 'RL/LL', 'RR/LL', 'LL/RR', 'VH/VV', 'VH/HH',
'HV/VV', 'HV/HH', 'VV/HH', 'HH/VV', 'Q/I', 'U/I', 'V/I'
other => don't use this option.
SYMBOL......Symbol to use when plotting.
1: Plus sign 13: Star of David
2: Cross (X) 14: Seven-pointed star
3: Circle 15: Eight-pointed star
4: Box 16: Nine-pointed star
5: Triangle 17: Ten-pointed star
6: Diamond 18: 11-pointed star
7: Pentagon 19: 12-pointed star
8: Hexagon 20: 13-pointed star
9: Septagon 21: 14-pointed star
10: Octagon 22: Plus (+) with gap
11: Nine-gon 23: Cross (X) with gap
12: Five pointed star 24: Vertical line
0 => 2 Cross (X) (FACTOR >=0) or
no point plotting (FACTOR < 0).
FACTOR......0 => 1. Scale symbol size by FACTOR.
FACTOR < 0 => connect points with lines, scale points by
-FACTOR. Line drawing is disabled when plotting a model
or when x,y are two of u,v,w.
LTYPE.......Labelling type, see HELP LTYPE for details:
1 = border, 2 = no ticks, 3 or 7 = standard, 4 or 8 =
relative to ref. pixel, 5 or 9 = relative to subimage
(BLC, TRC) center, 6 or 10 = pixels. 7-10 all labels
other than tick numbers and axis type are omitted.
Less than 0 is the same except that the plot file
version number and create time are omitted.
Add n * 100 to alter the metric scaling.
DOTV........> 0 => plot directly on the TV device, otherwise
make a plot file for later display on one or
more devices (including the TV if desired).
GRCHAN......Graphics channel (1 - 7) to use for line drawing.
0 => 1.
XYRATIO.....Scale the X axis longer than the Y by XYRATIO.
If DOTV > 0, 0 -> fit to the TV window
If DOTV <= 0, 0 -> 1.
BADDISK....The disk numbers to avoid for scratch files (sorting
tables mostly).
EXPLAIN SECTION