CoEPP RC
 

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tier3:faq:fast_rootdata_processing_tips [2014/03/17 11:51]
antonio created
tier3:faq:fast_rootdata_processing_tips [2014/03/17 12:00]
antonio
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 ===== Only read data that will be used ===== ===== Only read data that will be used =====
  
-Below is TTree processing code written in C++. The program produces a ROOT file that contains a histogram of the "​MET"​ (Missing Transverse Momentum) distribution in top-quark pair events at the LHC. +Below is TTree processing code written in C++. The program produces a ROOT file that contains a histogram of the "​MET"​ (Missing Transverse Momentum) distribution in top-quark pair events at the LHC. In this specific example we are accessing files using xrootd. The files are added together into a TTree chain. Fast processing is facilitated when we exactly tell ROOT which branches of TTree objects we wish to load. Initially we set the branch status to 0 for all branches, and then add set the status of the branch of interest to true. This addition to this piece of code made for a factor 25 increase in processing speed. ​  
  
 <​code>​ <​code>​
tier3/faq/fast_rootdata_processing_tips.txt · Last modified: 2014/03/17 12:00 by antonio
 
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