ROOT::Math::Util Namespace Reference

Description

namespace defining Utility functions needed by mathcore

Functions
template<class T >
T	EvalLog (T x)
	safe evaluation of log(x) with a protections against negative or zero argument to the log smooth linear extrapolation below function values smaller than epsilon (better than a simple cut-off) More...
template<class T >
std::string	ToString (const T &val)

Function Documentation

EvalLog()

template<class T >

T ROOT::Math::Util::EvalLog ( T  x )

inline

safe evaluation of log(x) with a protections against negative or zero argument to the log smooth linear extrapolation below function values smaller than epsilon (better than a simple cut-off)

Definition at line 56 of file Util.h.

                         {
      static const T epsilon = T(2.0 * std::numeric_limits<double>::min());
#if !defined(R__HAS_VECCORE)
      T logval = x <= epsilon ? x / epsilon + std::log(epsilon) - T(1.0) : std::log(x);
#else
      T logval = vecCore::Blend<T>(x <= epsilon, x / epsilon + std::log(epsilon) - T(1.0), std::log(x));
#endif
      return logval;
   }

Referenced by ROOT::Minuit2::FumiliMaximumLikelihoodFCN::operator()().

ToString()

template<class T >

std::string ROOT::Math::Util::ToString

(

const T &

val

)

Utility function for conversion to strings

Definition at line 42 of file Util.h.

   {
      std::ostringstream buf;
      buf << val;
 
      std::string ret = buf.str();
      return ret;
   }

Referenced by ROOT::Math::IBaseParam::ParameterName().