text: #include <iostream>
  #include <vector>
  #include <math.h>
  #include <cmath>
  
  class Pair ;
  class Center ;
  
  class Measure
  {
  public:
      Measure() ;
  
      double single_Distance( Center center, Pair point ) ;
      double  total_Distance( Center center, std::vector<Pair> points, bool forAllPairs=false ) ;
      double  all_totalDistances( std::vector<Center> centers, std::vector<Pair> points ) ;
      double std_deviation( Center center, std::vector<Pair> points, bool forAllPairs=false );
  
      void set_closest_center( Pair* p_point, std::vector<Center> centers, int display = -1 ) ;
  };
  