fix: eval_auto_bounds returns good value for pt==pt_low

[HeinerTholen]

Same as #15282.

(This fixes an error where eval_auto_bounds would return zero if the pt value at lower bound is given.)

[cmsbuild]

A new Pull Request was created by @HeinerTholen for CMSSW_8_1_X.

It involves the following packages:

CondTools/BTau

@ggovi, @cmsbuild, @davidlange6 can you please review it and eventually sign? Thanks.
@apfeiffer1 this is something you requested to watch as well.
@slava77, @smuzaffar you are the release manager for this.

cms-bot commands are list here #13028

[davidlange6]

please test

[cmsbuild]

The tests are being triggered in jenkins.
https://cmssdt.cern.ch/jenkins/job/ib-any-integration/14263/console

[ggovi]

+1

[cmsbuild]

This pull request is fully signed and it will be integrated in one of the next CMSSW_8_1_X IBs after it passes the integration tests. This pull request requires discussion in the ORP meeting before it's merged. @slava77, @davidlange6, @smuzaffar

[davidlange6]

Hi @HeinerTholen @ggovi - this change is naively unusual - is there more of an explanation elsewhere? (or maybe its just the consumer code that I need to be pointed to)

[HeinerTholen]

Hi @davidlange6 @ggovi, @imarches, @pvmulder
this is a minor bug, here's the according hn message: https://hypernews.cern.ch/HyperNews/CMS/get/btag/1322.html

The code is used by analysis users to retrieve btag scale factors. Only when a pt value exactly at the lower bound is given, a value of zero was returned. Since this is rarely the case, it's a minor bug, I would say. But it should be fixed.

[davidlange6]

i misread the code before - looks good to me now (though perhaps its more usual to include the lower limit in the bin rather than the upper limit..) Thanks