need for automatic detection of numerical underflows in histograms

[slava77]

In data/MC comparisons for tracking we were hit by the limits of TH1F numerical precision.
Histograms with more than around 1e7 entries in a bin will stop accumulation in that bin (because within numerical precision x + 1. == x).

It may be useful to have a generic feature in MonitorElement or DQMAnalyzers to e.g. once per lumi (or more often) to check if the histograms have any bins with entries that would underflow a fill (with some configurable weight; default of 1).
The same could be done per Fill call, but it could be a bit expensive CPU-wise.

@cms-sw/dqm-l2
@dbruschi

[cmsbuild]

cms-bot internal usage

[cmsbuild]

A new Issue was created by @slava77.

@Dr15Jones, @sextonkennedy, @rappoccio, @smuzaffar, @antoniovilela, @makortel can you please review it and eventually sign/assign? Thanks.

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[makortel]

assign dqm

[cmsbuild]

New categories assigned: dqm

@rvenditti,@syuvivida,@tjavaid,@nothingface0,@antoniovagnerini you have been requested to review this Pull request/Issue and eventually sign? Thanks