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Basic Information on uvplt
Task: uvplt
Purpose: Make plots from a UV-data base on a PGPLOT device.
Categories: uv analysis, plotting
UVPLT - Plot a variety of quantities from visibility data bases.
Options are available to time average data (plot with optional
error bars) and to plot different baselines on separate
sub-plots on each page plus many others.
Key: vis
The input visibility file(s). Multiple input files and wild card
card expansion are supported.
No default
Key: line
This is the normal linetype specification. See the help on line
for more information. The default is all channels.
Note that if more than one channel is selected, the ones with good
flags are vector averaged into one point unless options=nofqav is
used. See also the average= keyword below
Key: select
This selects which visibilities to be used. Default is all
visibilities. See the Users Guide for information about how
to specify uv data selection.
Default is all data
Key: stokes
Select Stokes parameter(s) or polarization(s) from:
xx, yy, xy, yx, i, q, u, v,
rr, ll, rl, lr
Default is all polarizations or Stokes parameters present
Key: axis
Two values (minimum match active), one for each of the x
and y axes chosen from:
time [time in DD HH MM SS.S format]
dtime [time in decimal days format]
amplitude, real, imag [natural units; Jy]
phase [degrees]
uu, vv [u & v in klambda]
uc, vc [u,& v, -u & -v in klambda]
uvdistance [sqrt(u**2+v**2)]
uvangle [uv pos'n angle clockwise from v axis]
hangle [hour angle in HH MM SS.S]
dhangle [hour angle in decimal hours]
parang [parallactic angle in degrees]
Defaults are axis=time,amp (x and y axes).
Key: xrange
Plot range in the x-direction
If axis = uu, vv, or uvdistance [kilo-lambda; 2 values]
unless OPTIONS=NANOSEC; then nanoseconds]
If axis = uvangle [degrees; 2 values]
If axis = time [dd,hh,mm,ss.s; 8 values]
If axis = dtime [decimal days; 2 values]
If axis = amplitude, real, imag [natural units; 2 values]
If axis = phase [degrees; 2 values]
If axis = hangle [hh,mm,ss.s; 6 values]
If axis = dhangle [decimal hours; 2 values]
If axis = parang [degrees; 2 values]
Default is to self-scale (see also OPTIONS=XIND).
Key: yrange
Plot range in the y-direction as for the x axis. The
default is to self-scale (see also OPTIONS=YIND).
Key: average
The averaging time in minutes (unless OPTIONS=DAYS,HOURS,SECONDS).
Averaging is reset at frequency, source, or pointing centre
changes. Individual baselines and polarizations are averaged
separately (unless OPTIONS=AVALL). If you have selected multiple
channels and you also ask for time averaging, then all the
selected channels are averaged together in the time interval.
If you wish to use OPTIONS=AVALL to average everything on
the one subplot (e.g. polarizations) but don't want temporal
averaging, set AVERAGE to less than one integration.
Default is no averaging.
Key: hann
Hanning smoothing length (an odd integer < 15). Is applied
after any time averaging and INC selection. Useful for amplitude
or phase, say, plotted against time. Error bars remain unaffected
by Hanning smoothing. Currently, the Hanning smoothing is unaware
of source or frequency changes. Use SELECT if you have boundary
problems.
Default is no smoothing (hann = 1).
Key: inc
Plot every INCth point (on each sub-plot) that would normally
have been selected. Useful if you don't want to average, but
want to cut down on the number of plotted points. Beware of
increments that divide exactly into the number of baselines
in time ordered data.
Default is 1.
Key: options
Task enrichment options. Minimum match is effective.
nocal Do not apply the gain corrections
nopol Do not apply the polarization leakage corrections
nopass Do not apply the bandpass corrections
nofqav By default, uvplt averages together all channels from
a visibility record before plotting. The nofqav option
disables this, and causes individual channels to be
plotted.
nobase Plot all baselines on the same plot, otherwise
each baseline is plotted on a separate sub-plot.
2pass Normally uvplt makes assumptions about what it is
expecting to find in the data with regards polarizations
and baselines. Under some conditions, uvplt may
report that it has not allocated sufficient buffer
space. This option instructs uvplt to make two passes
through the data, the first to accumulate precise
information on the contents of the selected data so
that buffer space is optimally allocated.
scalar Do scalar (average amplitudes or phases) rather than
vector (average real and imaginary) averaging.
This is useful if the visibilities are uncalibrated &
the phase is winding over the averaging interval & you
would like an averaged amplitude. Scalar averaged phase
is not very meaningful in general.
avall If you are averaging in time, then average all data
selected on each sub-plot together. E.g. all selected
polarizations, and, if OPTIONS=NOBASE, all baselines
as well. If you wish to average all the things on
one subplot together but without temporal averaging,
just set the averaging time to less than one integration.
unwrap When plotting phase, try to unwrap it so that
say, if one point is 179 deg and the next -179,
they will be plotted as 179 and 181 deg. NOTE:
Unwrapping noise can be VERY misleading.
rms Draw error bars (+/- 1 standard deviation) on the plot if
averaging is invoked.
mrms Draw error bars (+/- 1 standard deviation in the mean)
on the plot if averaging is invoked.
noerr The automatically worked out min and max plot limits
will NOT include the ends of the error bars.
all Plot flagged and unflagged visibilties
flagged Plot only flagged visibilities
The default is to plot only unflagged (good) visibilities
ALL overrides FLAGGED
nanosec u and v are plotted in nano-seconds rather than k-lambda
days The averaging interval is in days rather than minutes
hours The averaging interval is in hours rather than minutes
seconds The averaging time is in seconds rather than minutes
xind If the x-axis is self-scaled, then unless OPTIONS=NOBASE,
setting XIND will cause each sub-plot to have the x-axis
self-scaled independently. The default is that the x-range
used is that which encompasses the ranges from all sub-plots.
yind The equivalent for the y-axis
equal Plot x and y with equal scales. Useful only for plots
like AXIS=UU,VV. Does not mean the plot will necessarily
be square
zero Plot the x=0 and y=0 lines
symbols Each file is plotted with a different plot symbol
nocolour
Each file is plotted with the same colour (white). By
default and when there is only one polarization, each
file has a separate colour.
dots If time averaging is invoked, plot the data with dots
rather than filled in circles. These plot much faster
on hardcopy devices.
source Put the source name rather than the file name in the
plot title
inter After the plot is drawn, you get a chance to redraw
the plot with a different x- and y-range, and also
on a different device. In this way you can make a
hard-copy without re-running the program. In this case,
points outside of the user specified x,y-range are
ARE included in the plot buffer, so that if you redefine
the ranges, those points are available for plotting.
log Write the values and errors (if averaging) that are
plotted into the log file. No attempt to separate
baselines is made, except that automatically obtained
by not setting OPTIONS=NOBASE
Key: device
PGPLOT plot device/type. No default.
Key: nxy
Number of plots in the x and y directions for when plotting
each baseline separately. Defaults try to choose something
sensible.
Key: size
PGPLOT character sizes, in units of the default size (i.e., 1)
First value is for the labels, the second is for the symbol size
Defaults depend upon the number of sub-plots. The second value
defaults to the first.
Key: log
The output logfile name. The default is the terminal.
Key: tab
Special tabular output of the plotted data. Default none.
Currently the raw X and Y values are written out.
Example units: Time in seconds. Phases in degrees.
Key: comment
A one line comment which is written into the logfile.