Dynamic Histograms

As described above, it is often useful to have the events be delimiters for states of the computation. Once this is done, one wants statistical information about the distribution of state durations. xhist is an interactive histogram-inspection tool that displays this distribution for a chosen state. Since the visual appearance of such histograms are very sensitive to the upper and lower limits and the number of ``bins'' in the histogram, xhist provides a way to quickly and interactively adjust these parameters with scrollbars in the histogram window. A movable hair provides to-the-microsecond readings for the peaks in the histogram.