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Chapter 15, Xgig TraceView Histograms Histogram Overview
366 Xgig Analyzer User’s Guide
Histogram Overview
The histogram can graphically represent the entire trace from start to end. It also allows you to
expand and collapse the view of the trace to look at a graphic display of a detailed portion of the
trace. The histogram only represents the trace information for the ports currently selected. If you
change the ports that are selected for the current view, the histogram changes to show the data for
those ports only. The histogram display is divided into two areas:
• The upper part of the histogram shows a detail area of the trace. The gray area in the upper
histogram corresponds to the events shown in the spreadsheet area (listing of events).
• The lower histogram represents the entire trace, or the extent of a trace you want to view. The
gray area on the histogram corresponds to the detail area.
An example of the histogram area is show below.
Figure 167: Example Histogram Display
Using the Detail Area Histogram (upper histogram)
Drag the gray area to move around in the trace. The size of the gray area will change depending on
how much of the trace is displayed in the listing of events. You can also navigate to an area of the
trace by double-clicking on the location in time you want to display.
Using the Entire Trace Histogram (lower histogram)
The gray box on the lower histogram can be resized to zoom into a smaller area in the trace. This
is reflected in the upper histogram.
The yellow extent marks can be moved to narrow the view of the trace. Click and drag with the
mouse to move the extent marks. By narrowing the extent marks that narrow the gray box that
defining the detail area, you can see a graphic display of a very small time slice in the trace in the
upper histogram.
If you move the yellow start and/or end extent markers to select custom time extents, data
displayed is intersection of user set time extents and time extents determined by the state of T1/T2
button. This is true for event grid, DWORD grid, Exchanges View, and TSV. Depending on
custom time extents selected, it is possible for an exchange to be inside the time slice but for some
of the frames within that exchange to be outside the time slice. If some of the frames under an
expanded exchange fall outside the current time slice, Exchanges View will display place holder
frames for each of the frames outside the time slice. An example of a decode for placeholder
frames is “frame is clipped by current time extents”. Synchronization is disabled for the
placeholder frames.