msplot - Tool

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1.3.3 msplot - Tool

Plot data from a measurement set
Requires:

Synopsis

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.

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.
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. funcion. For example, subplot=131 will yeild a plot of three rows of plots.fntvwy
Data Sselection - 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.
(Un)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. (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. Warning: This function clears all flags, all data will be unflagged with this method.

Methods

??	Construct a msplot tool for plotting measurment sets
??	Set the measurement set to be plotted.
??	Clear the plotting window or a particular panel, or all panels.
??	Like the Emperor’s New Clothes.
??	Reset the state of MS plot back to its default state.
??	Close the measurement set being used.
??	See done – close and done do the same thing.
??	Close the current MeasurementSet, and destroy the plotter – ending all plotting.
??	Set the style of the plot.
??	List a short summary, description, of the data in the open measurment set.
??	Select a subset of the measurement set to operate on.
??	Set the scope of flagging extension
??	Specify which data is to be averaged in the MS (or selected MS).
??
??
??	A generic plotting routine for Measurement sets.
??	Routine for checking the sanity of a plotxy plot.
??	Plot the first set of iterative plots.
??	Continue plotting on an iteration axes.
??	Stop an iterative plot.

??	Save the currently plotted image.
??	Mark a rectangular region to flag or to investigate the data in the area.
??	Set flags for all selected regions marked using mp.markregion()
??	Unset flags in all regions marked using mp.markregion() Similar to the mp.flagdata()
??	Clear all flags in the table. Note: This clears all flags and should be used with caution.
??	Print info about data selected using mp.markregion().
??	Save current flags, applied to the current measurement set with a version name.
??	Restore flags for the current Measurement Set.
??	For the current measurement set delete a saved flag_version.
??	Print out a list of saved flag_versions, for the current Measurement Set.

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