Content-type: text/html Manpage of at_uvplt


Section: User Commands (1)
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at_uvplt - Make plots from a UV-data base on a PGPLOT device.  




uv analysis, plotting  


UVPLT plots 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.  


The input visibility file(s). Multiple input files and wild card card expansion are supported. No default
This is the normal linetype specification. See the help on "line" for more information. The default is all channels.
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
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
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]
  ytime                    [time in decimal years 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
  hangle                   [hour angle in HH MM SS.S]
  dhangle                  [hour angle in decimal hours]
  lst                      [local sidereal time in decimal hr]
  az                       [azimuth in degrees]
  el                       [elevation in degrees]
  airmass                  [airmass=1/sin(el)]
  jyperk                   [system gain, in Jy/K]
  rms                      [theoretical visibility noise rms, in
                            flux units]
  freq                     [frequency, in GHz]
  parang                   [parallactic angle in degrees]

NOTE: parang is the true parallactic angle of the source, which can be quite different from the angle between source and antenna feed (Miriad variable chi).

Defaults are axis=time,amp (x and y axes).

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]
  If axis = az or el              [degrees;       2 values]
  If axis = airmass               [natural units; 2 values]
  If axis = jyperk                [Jy/K;          2 values]
  If axis = rms                   [flux units;    2 values]
  If axis = lst                   [decimal hours; 2 values]
  If axis = freq                  [GHz;           2 values]

For axis types other than 'time' or 'hangle', one or other of the limits may be set with the other self-scaled by specifying the lower limit as 'min' and the upper as 'max' (or simply omitting it). For example,


self-scales the lower limit while pinning the upper limit to zero, whereas either of the following


set the lower limit to zero while self-scaling the upper limit.

Default is to self-scale both limits (see also OPTIONS=XIND).

Plot range for the y-axis as for the x-axis. The default is to self-scale (see also OPTIONS=YIND).
The averaging time in min (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.
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).
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.
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.  Note that this option is not active when time
         averaging is invoked (frequency averaging is always
         done then).

 nobase  Plot all baselines on the same plot, otherwise
         each baseline is plotted on a separate sub-plot.

 notitle Do not write any title on the plot.  Probably most
         useful if plotting all baselines on the same plot
         (using the "nobase" option).

 2pass   Normally uvplt makes assumptions about what it is
         expecting to find in the data regarding 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
 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
         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
         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
Second line of title for plot (the first line is generated automatically). Default is no sub-title.
PGPLOT plot device/type. No default.
Number of plots in the x and y directions for when plotting each baseline separately. Defaults try to choose something sensible.
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.
The output logfile name. The default is the terminal.
A one line comment which is written into the logfile.

_uvplt.for,v 1.1 2011/06/01 04:31:59 pteuben Exp $




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Time: 18:35:38 GMT, July 05, 2011