OO programming

[mickey]

Hello,
I have this class:

class Value {
  public:
   double _value;
   bool _missed;
};
class Feature {
    double _mean;
    vector<Value> _featVector;
    void computeMean() {
       for (int i=0; i < _featVector.size(); ++i) {
         sum += _featVec[i]._value;
       }
      _mean = sum / _featVec.size();
     }
     void normalize() {  
          for (int i=0; i < _featVector.size(); ++i) {
                _featVec[i]._value = /*normalization equation */
      }
}
 
class Datas {
    vector<Feature> _fet;
public:
 
   void computeMean() {
            for(int i=0; i < _feat.size(); ++i) 
                      _feat[i].computeMean();
   }
    void normalize() {
            for(int i=0; i < _feat.size(); ++i) 
                      _feat[i].normalize();
   }
//main.cpp
Datas data;
data.computeMean();
data.normalize();

class Value {
  public:
   double _value;
   bool _missed;
};
class Feature {
    double _mean;
    vector<Value> _featVector;
    void computeMean() {
       for (int i=0; i < _featVector.size(); ++i) {
         sum += _featVec[i]._value;
       }
      _mean = sum / _featVec.size();
     }
     void normalize() {  
          for (int i=0; i < _featVector.size(); ++i) {
                _featVec[i]._value = /*normalization equation */
      }
}

class Datas {
    vector<Feature> _fet;
public:
   
   void computeMean() {
            for(int i=0; i < _feat.size(); ++i) 
                      _feat[i].computeMean();
   }
    void normalize() {
            for(int i=0; i < _feat.size(); ++i) 
                      _feat[i].normalize();
   }
//main.cpp
Datas data;
data.computeMean();
data.normalize();

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Beyond that utility of some things, the point is: Feature is able to compute the mean and normalization on itself BUT to compute it It's necessary call it from one other class....; is it good?
Furthermore: Will it better: class Feature : public vector<Value> { .....}

I hope of many opinions,