Description

The msplot \tool\ is a plotting tool for a measurement sets.

The functionality of the msplot \tool\ extends that of the tableplot \tool\ to add knowledgable about measurement sets.

The msplot \tool\ does for measurement sets what the tableplot \tool\ does for tables. Much of the functionality is similar to that of tableplot \tool\ and it may be useful to read the tableplot \tool\ documentation.

There is also a similar plotting tool for calibration data, calplot tool.  The calplot \tool\ documentation may be useful to read since the calplot \tool\ is similar to msplot \tool\

Overview of msplot \tool\ functionality

At present, the msplot \tool\ plots from a single measurment sets only. Eventually data from more than one measurement set will be able to be accessed and plotted at the same time. Plots from the same MeasurementSet can be overlayed and more then one plotting panel can be created so different plots can be viewed simultaneously.

\begin{itemize}
\item{\bf Opening and Closing -} Before doing any plots you must call
mp.open with the
measurment set to be plotted. When finished use
mp.reset to reset
the measurment set; clear any data seletion done with
mp.setdata
as well as resets all of the plotting options back their default values.
mp.done to close
the measurement set, and the MS plotter.

\item{\bf Plotting -} The msplot \tool\ provides
several common plots that can be called easily, but the
mp.plotxy
function is a generic function for plotting.
The available common plots are:
mp.array,
mp.azimuth,
mp.baseline,
mp.elevation,
mp.hourangle,
mp.parallacticangle,
mp.uvcoverage,
mp.uvdist,
mp.vischannel, and
mp.vistime.

There are a number of plotting options that can be set to change the color, labels, symbol, number of plotting panels,
and many others. The mp.plotoptions function controls the plot options. It is important to note that once a plot option is set, it remains set until a subsequent call to the plotoptions method turns it off.

In addition iterative plots are provided. Iterative plots allow a user to iterate over some column plotting for that particular item. For example, a user may wish to plot the uv distances for each antenna separately by using the iteration value of 'ANTENNA' with the mp.dist function.

All of methods listed above have an interation parameter. Valid values for this parameter are: BASELINE, ANTENNA, FIELD, SPW, SCAN, FEED, and ARRAY_ID. To plot the the next plots in the iteration use the mp.iterplotnext.
To stop the iterative plot use mp.iterplotstop. Note that a useful operation to perform before doing and interative plot
is to set the subplot option to plot multiple plots with the mp.plotoptions function. For example, subplot=131 will yield a plot of three rows of plots.fntvwy

Data Selection - The mp.setdata function can be used to select which data is to be viewed, more precisely antennas, fields, UV ranges, and time selections can specified.

Flagging - }
(Un)Flagging can be performed both in memory and on disk. Flagging has
recently undergone some refactoring and it is now possible to save
what has been flagged in stages (versions). This gives msplot the
ability to undo flagging if so desired. Also is a new button on the
plotting window that turns on the flagging mode, allowing users to
interactively select the areas of interest. Soon there will be other
buttons for (un)flaggig, and for displaying information about the
flagged regions.

To (un)flag data first make a plot, see the plotting section above.
The next step is to mark a region(s) on the plot. This is done
with the
mp.markregion
function. If a specific region is given to this function this region
is used, otherwise the regions can be marked on the plotter by selecting
square regions with the mouse.

Now there are regions marked on the plot, there are three different
actions that can be taken at this point. The
mp.locatedata
function displays information about each of the points in the marked
regions. ({\bf Warning:} if a lot of points are selected a large
amount of data will be given to the logger, this can slow down the
logger drastically!) The other two actions that can be taken are
closely related
mp.flagdata
and
mp.unflagdata,
to flag or unflag data respectively. Both of these functions allow
the flagging to be done in memory (default) or on disk.

One final function for flagging is
mp.clearflags.
{\bf Warning: This function clears all flags, all data will be unflagged
with this method.}