msplot - Tool

Postscript file available

tool for MeasurementSet plotting, display, listing and editing
include "msplot.g"

Description

msplot provides a GUI-based tool for displaying the data (as line plots or gridded onto a raster) of various parts of a measurement set. It is built on top of the ms tool, allowing plotting of many of the variables accessible via the ms:ms.getdata function. msplot also supports interactive flagging of data in a measurement set. Non-interactive flagging is possible using the flagger tool or the autoflag tool.

Next to the Show label at the top, you will find a button that allows selection of one of possible plots, displays, and listings. In this context, a plot means a graph of plotted points (made using the pgplotter), a display means an image-like display of gridded data (made using the viewer), and a listing send various information to the logger. The most straightforward plot is X versus Y, where, for example, X could be selected to be Time, and Y could be selected to be field_id. Generally plotting visibility against something else will be more useful: for example, on the Y axis might be observed amplitude, and X might be uvdist. Use the plotflagged switch under the Options menu to control whether flagged points are visible. Use the multi-panel switch under Options to control whether multiple plots are displayed on the same page (as would be useful for e.g ATCA baseline plots. Summary and row-by-row listings are available, though the latter is quite underdeveloped currently.

The types of plots allowed are adapted to the type of data: for synthesis data, one can plot uv coverage and the data for a slice in the uv plane. For single dish data, one can plot the pointing coverage and the data for a slice in the sky plane.

For the Plot of X versus Y, the axes to be plotted can be chosen by selecting under the various buttons on the second row labelled X Axis and Y Axis. Iteration over various axes may be enabled by selecting buttons under the Iterate button. To stop an iteration or other operation, press the red Stop button. By suitable combination of these controls, you should be able to able to get a very wide range of useful X, Y plots.

For the Image display, visibility data are displayed as an image, gridded on axes: Interferometer, Row (Time), Channel, and Correlation. The choice of what form of visibility to show as brightness is controlled by the Image button.

Selection of the Measurement Set data to be shown is controlled by a number of buttons on the third row. Selecting one of these causes a frame to be shown directly underneath.

X, Y plot limits: The scaling for the plot axes may be specified using the entry boxes. The range of values in the plot may be filled into the box using the Ranges button at the right hand side.
Data selection: Ranges of quantities to be selected may be input via entry boxes. The range of values in the measurement set may be filled into the box using the Ranges button at the right hand side. A selection may then be made and the Ranges recalculated.
Spectral selection: Channels to be plotted may be selected with or without averaging. One specifies the number of desired output channels (NCHAN), the input channel to start with (START), the number of input channels to step between output channels (STEP), and the number of input channels to average per output channel (WIDTH). For example, to plot each of 32 channels, use NCHAN=32, START=1, STEP=1, WIDTH=1. To plot the average of all the channels use NCHAN=1, START=1, STEP=1, WIDTH=32. NCHAN=3, START=2, STEP=5, WIDTH=3 will plot 3 output channels, each the average of channels [2,3,4,5,6], [5,6,7,8,9], and [8,9,10,11,12].
Polarization selection: The names of the requested polarizations may be input: e.g. I Q U V or RR RL LR LL, etc..

The control arguments for msplot are saved and restored between executions, and in addition the arguments may be reset to the default values. All of this is possible from the Arguments button at the bottom of the GUI.

When plotting, msplot works by issuing commands to the pgplotter. The plot may be saved in AIPS++ plot file format (actually an AIPS++ table), or written as a postscript file.

When displaying, msplot uses the viewer. It first constructs an image with the relevant axes (by gridding the data onto a cube), and then sends it to the viewer for display. All the capabilities of the viewer may be used to control the display.

Next: Editing via the viewer Up: ms - Module Previous: msplotapplyflags - Function Contents Index

	Package	general
	Module	ms