Compute the mean of the variable V. More...

#include <STK_Stat_Functors.h>

Public Types
typedef Derived::Type	Type

Public Member Functions
	MeanOp (ExprBase< Derived > const &V)
	constructor

Type const	operator() () const

template<class Weights >
Type const	operator() (ExprBase< Weights > const &w) const

Protected Attributes
Derived const &	V_

Detailed Description

template<class Derived>
struct STK::Stat::MeanOp< Derived >

Compute the mean of the variable V.

Definition at line 297 of file STK_Stat_Functors.h.

Member Typedef Documentation

◆ Type

template<class Derived >

typedef Derived::Type STK::Stat::MeanOp< Derived >::Type

Definition at line 299 of file STK_Stat_Functors.h.

Constructor & Destructor Documentation

◆ MeanOp()

template<class Derived >

STK::Stat::MeanOp< Derived >::MeanOp ( ExprBase< Derived > const & V )

inline

constructor

Definition at line 301 of file STK_Stat_Functors.h.

301 : V_(V.asDerived())

302 { STK_STATIC_ASSERT_ONE_DIMENSION_ONLY(Derived);}

STK_STATIC_ASSERT_ONE_DIMENSION_ONLY

#define STK_STATIC_ASSERT_ONE_DIMENSION_ONLY(EXPR)

Definition STK_StaticAssert.h:151

STK::Stat::MeanOp::V_

Derived const & V_

Definition STK_Stat_Functors.h:337

References STK_STATIC_ASSERT_ONE_DIMENSION_ONLY.

Member Function Documentation

◆ operator()() [1/2]

template<class Derived >

Type const STK::Stat::MeanOp< Derived >::operator() ( ) const

inline

Returns: the mean of the variable V
$\hat{\mu} = \frac{1}{n} \sum_{i=1}^n V(i)$

Definition at line 306 of file STK_Stat_Functors.h.

    {
      // no samples
      if (V_.empty()) { return Type(0);}
      // sum the samples
      Type sum  = 0.;
      for (int i=V_.begin(); i<V_.end(); i++) { sum += V_[i];}
      return sum /= (Type)(V_.size());
    }

References STK::Stat::sum(), and STK::Stat::MeanOp< Derived >::V_.

◆ operator()() [2/2]

template<class Derived >

template<class Weights >

Type const STK::Stat::MeanOp< Derived >::operator() ( ExprBase< Weights > const & w ) const

inline

Returns: the weighted mean value of the variable V
$\hat{\mu} = \frac{1}{\sum_{i=1}^n w(i)} \sum_{i=1}^n w(i) V(i).$

Parameters

w	the weights

Definition at line 320 of file STK_Stat_Functors.h.

    {
      STK_STATIC_ASSERT_ONE_DIMENSION_ONLY(Weights);
      // no samples
      if (V_.empty()) { return Type(0);}
      // sum the weighted samples
      Type sum  = 0.0, sumweights= 0.0;
      for (int i=V_.begin(); i<V_.end(); i++)
      {
        Type const weight = std::abs(w[i]);
        sumweights += weight;
        sum        += weight * V_[i];
      }
      // compute the weighted mean. If all weights are 0, we get 0
      return (sumweights) ? sum /= sumweights: Type(0);
    }