There seems to be a few other programs floating around the net by the same name. This one was written by Tim Shepard while doing his S.M. thesis "TCP Packet Trace Analysis" for David Clark at the MIT Laboratory for Computer Science. The thesis can be ordered from MIT/LCS Publications. Ordering information can be obtained from +1 617 253 5851 or send mail to publications@lcs.mit.edu. Ask for MIT/LCS/TR-494. Or you can get it on the net free of charge from <ftp://ftp.lcs.mit.edu/pub/lcs-pubs/tr.outbox/MIT-LCS-TR-494.ps.gz>.
You may also look at the program's web-site xplot for the latest version of the program.
Basic Usage
Viewing xplot graph(s) (commonly named as files with the .xpl suffix) is as simple as saying :
xplot file1.xpl [file2.xpl {. . .} ]
You may use the Left-Mouse button to drag and select a specific area in the graph to zoom on it. You may keep repeating this procedure to zoom in more and more to see any specific area of the graph in more and more detail. The zoom views are stored in a stack internally, and clicking the Left-Mouse button on the graph lets you zoom-out level by level popping out the stack. The Middle-Mouse button (clicking and dragging) lets you scroll the graph. The Right-Mouse button closes the graph being viewed.
The -x option can be useful if you are viewing related graphs (the forward and reverse directions of a connection, for example) to line-up the x-axes of both the graphs.
Using :
xplot -x a2b_tsg.xpl b2a_tsg.xplfor example, sets their x-axes in sync so that, zooming in on one of the graphs, also zooms the other graph, so that you see the same time-scales on both the graphs all the time. Similar semantics are also supported for the y-axis with the -y option.
Generating Postscript
Clicking the Left-Mouse Button with the SHIFT key pressed, drops a postscript version of the graph being viewed in the working directory. The postscript files are named Title.PS.# where Title is the title of the graph and # is a serial number that gets from 0, 1, ... used so that files do not overwritten accidentally in the working directory.
Clicking the Middle-Mouse Button with the SHIFT key pressed drops a postscript file of smaller size that is good for including in a paper, for example. Clicking the Right-Mouse Button with the SHIFT key pressed also drops a smaller size postscript file, but the graph is made smaller vertically.