AIPS HELP file for UVPLT in 31DEC24
As of Sat Apr 27 4:19:37 2024
UVPLT: Plots data from a u,v data base: multi-channel version
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 Input UV file disk unit #
SOURCES Sources to plot, ' '=>all.
QUAL -10.0 Qualifier -1=>all
CALCODE Calibrator code ' '=>all
STOKES Stokes type to select.
SELBAND Bandwidth to select (kHz)
SELFREQ Frequency to select (MHz)
FREQID Freq. ID to select.
TIMERANG Time range to select
ANTENNAS Antennas to plot
BASELINE Baselines with ANTENNAS
UVRANGE UV range in kilolambda.
SUBARRAY 0.0 1000.0 Subarray, 0 => all
BCHAN 0.0 4096.0 1st spectral channel #
ECHAN 0.0 4096.0 Last spectral channel #
NCHAV 0.0 4096.0 # of channels to average
CHINC 0.0 4096.0 Increment in channel #
BIF Low IF number to plot
EIF Highest IF number to plot
DOCALIB -1.0 101.0 > 0 calibrate data & weights
> 99 do NOT calibrate weights
GAINUSE CAL (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
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.
XINC 0.0 9999.0 Plot every XINC'th visibility
0 => 1.
APARM Control parameters for UV
1: min of W range, klambda
2: max of W range, klambda
3: plot both halfs of UV(W)?
0 => plot both halfs
-1 => plot one UV half
+1 => plot another U,V
half
10: > 0 -> exclude cross-corr
BPARM Control parameters
1 : X-axis type 0=>UV dist
2 : Y-axis type 0=>Ampl
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 (IAT hours)
12=> log10 (ampl)
13=> weight
14=> HA (hours)
15=> elevation (deg)
16=> parallactic angle
17=> uv dist. (klambda)
along p.a.
18=> azimuth (deg)
19=> frequency
20=> channel
21=> baseline
3 : > 0.0 => fixed scale
< 0.0 => fixed range
4 : Xmin (fixed scale)
5 : Xmax (fixed scale)
6 : Ymin (fixed scale)
7 : Ymax (fixed scale)
SEE HELP
8 : Number of bins in plot.
<0 points and binned
9 : > 0 => list bin values.
10: > 0 => do not use array
for plot files
> 1 => do not use array
for TV plots
BPARM=6,7,2,0 generates
square UV coverage plots
SOLINT Time averaging interval (min)
< 0 -> scan average
DOACOR -1.0 1.0 > 0 include autocorrelations
DOSCALE -1.0 3.0 > 0 => Scale vis by source
flux; = 2 use spectral index
= 3 include curvature
DOWEIGHT -1.0 1.0 > 0 use weights in binning
REFANT 0.0 90.0 > 0 => use REFANT for plot
types 14, 15, 16, 18
ROTATE -360.0 360.0 uv p.a. for projection
(deg N->E); type 17 only
FACTOR -1000.0 1000.0 Scale dots by FACTOR
< 0 => connect dots too
DO3COLOR -1.0 1.0 > 0 use 3-color to separate
channels and IFs; see explain
< 0 black & white plot file
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 -10.0 10.0 > 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
IMSIZE Grid size for plot files
BADDISK Disk to avoid for scratch.
HELP SECTION
UVPLT
Type: Task
Use: Plots data from a u,v data base making a plot file. Calibration
information can be applied before plotting. If calibration
information is to be applied, the data must be in TB sort order.
The task now uses a new method of generating its plots - filling
in an array in memory and then displaying the plot as an image.
The labeling and the averaged bin values (if any) are plotted
separately. For large data sets, this is very much faster than
plotting individual samples to the TV and this generates
substantially smaller plot files which may be displayed more
rapidly. Note, however, that these plot files are images and so
may not fit on your TV if plotted by TVPL. When making plot
files, you may turn off this new method with BPARM(10).
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.
SOURCES....List of sources to be plotted. ' '=> all; if any starts
with a '-' then all except ANY source named.
QUAL.......Qualifier of source to be plotted. -1 => all.
CALCODE....Calibrator code of sources to plot. ' '=> all.
STOKES.....The desired Stokes type of the plotted data:
'I','Q','U','V', 'IV', 'IQU', 'IQUV'
'RR','LL', 'RL', 'LR', 'RRLL', 'RLLR', 'RLRL'
'VV','HH', 'VH', 'HV', 'VVHH', 'VHHV', 'HVHV'
'HALF', 'CROS', and 'FULL' have sensible interpretations
depending on the Stokes present in the data. The last in
each of the 3 rows above == 'FULL'. ' ' => 'FULL'
All selected Stokes will be plotted
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 or
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
overide that of FREQID. However, setting SELBAND and
SELFREQ may result in an ambiguity. In that case, the task
will request that you use FREQID. If all SELBAND, SELFREQ
and FREQID are not specified (<= 0) then the task will loop
over the frequency ID plotting all of them!
TIMERANG...Time range of the data to be plotted. In order:
Start day, hour, min. sec, end day, hour, min. sec.
Days relative to reference date.
ANTENNAS...A list of the antennas to plot. If any number is negative
then all antennas listed are NOT desired and all others
are. All 0 => list all.
BASELINE...Baselines are specified using BASELINE.
Eg. for baselines 1-6,1-8, 2-6 and 2-8
use ANTENNAS=1,2; BASELINE=6,8.
UVRANGE....Range of projected spacings to be plotted in 1000's of
wavelengths. 0 => 1, 1.E10
SUBARRAY...Subarray number to plot. 0 => all - the task will
loop over subarray number.
BCHAN......Beginning spectral line channel number. 0 => 1.
ECHAN......Ending spectral line channel number. 0 => max.
NCHAV......Number of spectral channels to average before plotting.
0 => 1. ECHAN will be adjusted downwards so that all
averages will include the same number of spectral
channels.
CHINC......Increment in spectral line channel number. 0 => NCHAV
Channels i to i+NCHAV-1 are averaged before plotting for
i = BCHAN to ECHAN by CHINC so plotted averages may be
separated in frequency or overlapped in frequency. Setting
CHINC to NCHAV is the most common usage.
BIF........First IF number to plot. 0 => 1
EIF........Last IF number to plot. 0 => highest
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 Cal. table to apply to the data if
DOCALIB=1. Refers to a CL table for multi-source data or
an SN table for single-source. 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 apply. <0 => apply no BL table, 0 => highest, if any.
FLAGVER....Specifies the version of the flagging table to be applied.
0 => highest numbered table. <0 => no flagging to be
applied.
DOBAND.....(multi-source) 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......(multi-source) specifies the version of the BP table to be
applied. 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).
XINC.......Plot every XINC'th visibility which might be plotted.
This used to be a very useful option when the plots were
written to the TV or plot file for each point. Now, when
the plots are prepared in memory and then dumped to the
device, it is far less useful.
0 => 1.
APARM......Control parameters specifically for UV depending on W range
This option can be usefull when investigating effect of the W term
on the imaging.
All baselines are converted to W>0
1: min W of W range to plot, in klambda
2: max W of W range to plot, in klambda
3: plot the mirrors UV(W)?
0 => plot both halfs of UV
-1 => plot one half of U,V (for W>0)
+1 => plot another half (mirror) of U,V (for W<0)
BPARM......Control parameters:
1,2 = type of X-axis and type of Y-axis- where,
1 = amplitude (Jy), 2 = phase (degrees),
3 = u,v distance (klambda), 4 = u,v p.a.(deg, N thru E)
5 = time (IAT days), 6 = u (+max at left, bottom)
7 = v, 8 = w (all in klambda),
9 = real part (Jy) 10 = imaginary part (Jy)
11 = time (IAT hours) 12 = log10 (amplitude)
13 = vis weight 14 = hour angle (hours)
15 = elevation (degrees) 16 = parallactic angle (deg)
17 = uv dist. in p.a. ROTATE 18 = azimuth (deg)
19 = frequency 20 = spectral/IF channel
21 = baseline (by antenna)
types 14, 15, 16 support planets if there is a PO table
**********************************************
Use -n to plot the parameter from max at left or bottom to min
at right or top rather than the usual order (opposite for u).
**********************************************
BPARM(1)=0 => 3 -- X-axis type is u,v, distance
BPARM(2)=0 => 1 -- Y-axis type is Amplitude (Jy)
For single-dish data: 1 and 9 are flux, 2 and 10 are offset, 3,
6, and 8 are longitude, 4 and 7 are latitude.
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, fully self-scaling. Each axis treated separately.
4 = Minimum of X-axis - used if BPARM(5) > BPARM(4).
5 = Maximum of X-axis - used if BPARM(5) > BPARM(4).
6 = Minimum of Y-axis - used if BPARM(7) > BPARM(6).
7 = Maximum of Y-axis - used if BPARM(7) > BPARM(6).
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.
NOTE: the task can force negative phases to be positive if
a fixed scale is chosen, but it will not force positive phases
to be negative. Thus, values > 360 or < -180 are not available.
This operation is also applied to UV position angle, hour
angle, parallactic angle, and azimuth axes.
8 = If = 0, plot each selected sample individually.
If > 0, plot bin averages in X of the specified quantity.
There will be BPARM(8) number of bins in the plot. For bins
with more than 2 entries the vertical height of the symbol
represents the standard deviation of the mean of the
distribution in the bin except that the minimum height
plotted = width of the + symbol. Self-scaling will be on
binned values.
If < 0, bin the data in abs(BPARM(8)) bins, but plot the
individual samples (as line type 4) as well as the bin
averages (as line type 3). Self-scaling will be on the
individual samples.
The binned values include individual samples outside the plot
range (BPARM(6) - BPARM(7)) but are then plotted only if they
fit in the plot range.
9 = If > 0, then the values and standard deviations in each bin
will be put in the message file (prio=5). Has no effect if the
plot is not binned.
10 If > 0, then the faster array method of plotting will not be
used when making plot files.
If > 1, then do not use the faster method of plotting for the
TV either. Watching the plot develop can be instructive but
can be literally 100's of times slower.
BPARM=6,7,2,0 will generate a UV coverage plot with identical U and
V limits.
SOLINT.....If not zero, average the data for SOLINT minutes or until a
scan break occurs. SOLINT < 0 -> very large so scan
averages.
DOACOR.....If > 0, then the auto-corelations, if there are any, will
also be plotted.
DOSCALE....> 0 => Scale visibility amplitudes by source fluxes from
source table; = 2 fit and use also spectral index; = 3
fit and use flux at 1 GHz, spectral index, and curvature.
DOWEIGHT...> 0 => use data weights in averaging the binned data
(BPARM(8) not zero).
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.
ROTATE.....Position angle, in degrees N thru E, for the projected uv
distance. This parameter is only used if BPARM(1)=17
or BPARM(2)=17.
FACTOR.....Multiplier to make plotted points larger or smaller.
abs (FACTOR)< 0.1 => 1. FACTOR < 0 => connect the dots
and draw the symbol.
DO3COLOR...> 0 => use 3-color vectors in the plot symbols to allow
the channels and IFs to be distinguished. BIF, BCHAN is
full red, EIF,ECHAN is full blue. IF is the outer loop,
so if there are 2 IFs, the channels and polarizations of
IF 1 will range from red to green and those of IF2 will
range from green to blue. Note that blue vectors may
overlap and obscure red ones.
< 0 on plot files => make a black on white plot. Use
DOCOLOR <= 0 in LWPLA
= 0 on plot files, color plotted points with standard
color for GRCHAN (default = 4 = cyan). Any DOCOLOR
works in LWPLA.
> 0 on plot files plots points in suitable colors (as
above) on a black background. DOCOLOR > 0 in LWPLA
is needed to see labels.
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.
BADDISK....Disk numbers to avoid for scratch files. Scratch files may
be created by the sorting routines if calibration or
flagging is applied.
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.
EXPLAIN SECTION
UVPLT: Plots data from a u,v data base making a plot file.
RELATED PROGRAMS: TKPL, LWPLA, TVPL
PURPOSE
UVPLT can be used to plot any pair of variables from a u,v data
base i.e. any of u, v, w, uv distance, uv position angle, visibility
amplitude, phase, real, imaginary. It is very useful as a diagnostic
tool. Some possible uses :
1. Plotting visibility amplitude or phase as a function of uv
distance to find a useful uv range for selfcalibration. Use the
averaging option.
2. Plotting visibility amplitude or phase of the residuals of a set
of clean components from a data base as a function of uv distance to
find bad points which can be clipped using task CLIP. The task UVSUB
can be used to subtract or add the visiblity corresponding to a set of
clean components. For the purpose of spotting bad visibility points it
is recommended that all clean components up to the first negative be
subtracted before running UVPLT.
3. Plotting u against v will give the uv plane coverage of the data
set.
4. Plotting visibility amplitude or phase as a function of uv
distance to guesstimate a reasonable value for the zero spacing flux to
be used in IMAGR. Values > 110-120 percent of the maximum correlated flux will
lead to spurious results in cleaning.
COMMENTS
BCHAN, ECHAN, BIF, EIF:
More than one frequency may be plotted from multi-channel, multi-IF
data sets. The data will be plotted at u,v,w values corrected to the
frequency of the individual channel and IF. This is useful in seeing
the effect of bandwidth synthesis.
DO3COLOR:
DO3COLOR > 0 requests the plot to use colors to distinguish
polarizations, spectral channels, and IFs. The actual logic is:
COLOR = 0
DO IF = BIF,EIF
DO CHAN = BCHAN,ECHAN BY CHINC
DO POL = 1,Npol
set and use COLOR
COLOR = COLOR + DeltaColor
END DO POL
END DO CHAN
END DO IF
where COLOR=0 is pure red, DeltaColor is set so that the last value of
COLOR is 1 which is pure blue. 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
LL in IF 1, cyan is RR in IF 2, and blue is LL in IF 2. If a
significant number of spectral channels are plotted, in one IF and one
polarization, then there will be virtually a continuum of spectral
colors from red at the lowest channels through green to blue at the
highest with only a subtle change of color between channels. Note
that the blue is plotted after the ble and so may overlap and obscure
the red.
UVRANGE :
Allows selection of points to be plotted on the basis of distance
from the centre of the uv plane.
AVERAGING :
A very nice option allows the averaging of the data into bins. The
average and rms in a bin is plotted in place of the individual values.
This is mainly useful for seeing the overall shape of the visibility
curve. Default scaling is by the extrema of the axes. BPARM(8)
switches on the averaging and sets the number of bins. The sign of
BPARM(8) controls whether the data averaging uses the data weight (< 0)
or is a simple average (> 0).
SCALING :
The default scaling is from the maximum to the minimum of an axis.
The entire data base must be read to determine the scaling so you can
halve the execution time of UVPLT by specifying the maximum and minimum
values. If BPARM(3) > 0.0, then BPARM(4) - BPARM(7) control the scaling
of the 2 axes. If, however, any of the BPARM4) - BPARM(7) is zero, then
that parameter will be self-scaled. If you actually want 0.0 for a
limit, set some small negative (for lower limits) or positive (for upper
limits) amount..
The option of setting BPARM(3) < 0.0 is useful to restrict the data
to some range, but still have a self-scaled plot. For example, BPARM =
3, 1, -1, 0, 0, 1.0, 10000 will plot amplitudes >= 1.0 against uv
distance, but the amplitude scale will only go up to the peak amplitude
in the data not to 10000 Jy. The X axis (uv distance) will self-scale
to cover the full range.
XINC :
Allows plotting of only every XINC'th point. The plotting of the
plot file can be extremely tiresome unless the number of points is
limited. A few thousand is usually reasonable.
REFERENCES
None.