OPETool is an analysis tool for
OccupancyPerEvent or OPE data which is in Release4.0. OPETool takes in RawData
? and analyses the OPE data for each threshold bin separately. At each threshold, some "n" number of channels out of the 128 channels on a chip is expected to fire on average. The probability distribution of frequency of getting "n" number of channels firing per one event is given by the Binomial distribution. The OPETool compares the observed variance of this distribution with the calculated variance -- there is a simple formula that relates mean to variance. The OPE "badness" parameter is defined as the ratio of these two variances. The badness parameter is output to the OpeSummary
? and can be viewed in the online Gui.
An example of the OPE plot for a chip is found [here]. Generally, the histogram is not plotted in 3D like here but is plotted in 2D with a color scheme that shows the height. In 3D, for each threshold, the distribution of events with n number of hits is seen to be a Binomial distribution.
The analysis results of Barrel 3 cold run can be found at OPEAnalysis.