safeLogRatio.cxx

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/*
   Copyright (C) 2002-2022 CERN for the benefit of the ATLAS collaboration
*/
 
#include "TrigBjetHypo/safeLogRatio.h"
 
#include <cmath>
#include <limits>
 
float safeLogRatio(float num, float denom) {
  // ep(silon) is the smallest non-subnormal number
  // the recyprocal of this should not overflow
  float ep = std::numeric_limits<float>::min();
  float ratio = (std::abs(denom) < ep ? INFINITY : num / denom);
  return std::abs(ratio) < ep ? -INFINITY : std::log( ratio );
}