SimpleStatistics.h

Go to the documentation of this file.

 
/* *************************************************************************/
#ifndef SIMPLESTATISTICS
#define SIMPLESTATISTICS
 
#include <limits>
#include <string>
#include <sstream>
#include "CppAddons.h"
 
// This define (or any other element put here) is needed for doxygen to work ok
// the nesting of groups in this file:
// http://stackoverflow.com/questions/40343396/
//      doxygen-grouping-classes-in-several-nested-groups
#define SIMPLESTATISTICS_ELEMENT_FOR_AVOIDING_ERROR_IN_NESTING_GROUPS_IN_DOXYGEN
 
 
/* ***************************************************************************
*
*   Overflow policies for the class SimpleStats.
*
***************************************************************************** */
template <typename T>
class SSOvPol_ThrowExc
{
 public:
 
    SSOvPol_ThrowExc(unsigned *n) {}
 
    bool full(void) { RUNTIMEEXCEP("Cannot hold more data"); }
 
};
 
template <typename T>
class SSOvPol_IgnoreMoreData
{
 public:
 
    SSOvPol_IgnoreMoreData(unsigned *n) {}
 
    bool full(void) { return(false); }
 
};
 
template <typename T>
class SSOvPol_Reset
{
 public:
 
    SSOvPol_Reset(unsigned *nd):n_{nd} {}
 
    bool full(void) { *n_ = 0; return(true); }
 
 private:
 
    unsigned * n_;
};
 
/* *****************************************************************************
*
*   Template class: SimpleStats
*
*******************************************************************************/
 
template <typename T, // type of the data
          class OverflowPolicy = SSOvPol_ThrowExc<T>, // policy of overflow
          unsigned MAXSIZE = std::numeric_limits<unsigned>::max() // max size
         >
class SimpleStats
{
 public:
 
    /* --------------------- Constructors ---------------------------- */
 
    SimpleStats(void):ovpol_{OverflowPolicy{&n_}} { reset(); }
    /* Copy constructors and assignments are generated implicitly by the
    compiler. */
 
    virtual ~SimpleStats(void) {}
 
    /* --------------------- Methods ---------------------------- */
 
    void reset(void) { n_=0; minimum_ = T{}; maximum_ = T{}; average_ = T{}; }
 
    void addDatum(T v)
    {
        if ((n_ == MAXSIZE)&&(!ovpol_.full())) return;
        if (n_==0)
        {
            minimum_=v;
            maximum_=v;
            average_=v;
        }
        else
        {
            if (v<minimum_) minimum_=v;
            if (v>maximum_) maximum_=v;
            T onebyn = static_cast<T>(1) / n_;
            average_ = (static_cast<T>(1) - onebyn) * average_ + onebyn * v;
        }
        ++n_;
    }
 
    unsigned sampleSize(void) const noexcept { return(n_); }
 
    T min(void) const noexcept { return(minimum_); }
 
    T max(void) const noexcept { return(maximum_); }
 
    T avg(void) const noexcept { return(average_); }
 
    std::string to_string(void) const noexcept
    {
        std::ostringstream s;
        s << "stats(" << n_ << "): min=" << minimum_ <<
              ", max=" << maximum_ <<
              ", avg=" << average_;
        return(s.str());
    }
 
 private:
 
    T minimum_, maximum_, average_;
    unsigned n_;
    OverflowPolicy ovpol_;
};
 
 
#endif
 // SimpleStatistics