Bootstrapping

Bootstrapping event fills

After processing an event, the AnalysisHandler can be queried for the fill indices and fill fractions in order to allow for correlating event fills across various histograms from multiple analsyses, e.g.

ah.collapseEventGroup()
print(ah.fillOutcomes())
print(ah.fillFractions())

Note that by default Rivet will only collapse the event groups to finalise the fill operation when the event number changes in order to account for correlated sub-events. That means that the fill outcomes will typically be lagging behind by one unit, unless collapseEventGroup() is called directly before the query.

If a file name is supplied to the AnalysisHandler via the setBootstrapFilename method this information will be dumped into a corresponding ASCII file.

Note that this file is updated for every event and will grow in size quickly!

The format is as follows:

two header lines at the top of the file (preceded by a #): one specifying the weight names and one the AO path name,immediately followed by a comma and the total number of bins of the AO (including under/overflows and masked bins)
three lines per event:
- one starting with a W listing the (multi-)weights
- one starting with an O listing the binary fill outcome
- one starting with an F listing the fill fractions

An example using a custom routine that only books a single 1D histogram with four (visible) bins could look like this:

# MEWeight NTrials Weight WeightNormalisation
# /MY_TEST/testHisto,6
W 4.788e-12 5 0.0382951 47.7771
O 0 1 0 1 0 0
F 0 1 0 1 0 0
W 3.26928e-13 16 19.8212 47.7771
O 0 1 0 0 0 0
F 0 2 0 0 0 0
W 6.4679e-11 11 20.3138 47.7771
O 0 1 0 0 1 0
F 0 1 0 0 1 0

Note that in the second event, the first visible bin was filled twice.