Persistent case

vector <float>  points_on_X(10); // Vector of 10 real numbers 
points_on_X[0] = 0.0; points_on_X[1] = 1.0; 
points_on_X[2] = 3.5; points_on_X [3] = 4.0; 
points_on_X[4] = 5.5; points_on_X[5] = 9.0; 
points_on_X[6] = 10.; points_on_X[7] = 15.; 
points_on_X[8] = 19.; points_on_X[9] = 20.; 

HepRef(PHisto1DVar) histo = 
  new (db_) PHisto1DVar( "Histo1DVar", points_on_X ); 

vector <float>  points_on_Y(10); 
points_on_Y[0] = 0.0; points_on_Y[1] = 1.0; 
points_on_Y[2] = 2.5; points_on_Y[3] = 4.0; 
points_on_Y[4] = 6.0; points_on_Y[5] = 9.0; 
points_on_Y[6] = 12.; points_on_Y[7] = 14.; 
points_on_Y[8] = 18.; points_on_Y[9] = 20.; 

HepRef(PHisto2DVar) histo = 
  new (db_) PHisto2DVar( "Histo2DVar", points_on_X, points_on_Y ); 

Transient case

T_Points_Vector points_on_X(10); // Vector of 10 real numbers 
points_on_X[0] = 0.0; points_on_X[1] = 1.0; 
points_on_X[2] = 3.5; points_on_X[3] = 4.0; 
points_on_X[4] = 5.5; points_on_X[5] = 9.0; 
points_on_X[6] = 10.; points_on_X[7] = 15.; 
points_on_X[8] = 19.; points_on_X[9] = 20.; 

Histo1DVar *histo = new Histo1DVar( "Histo1DVar", points_on_X ); 

T_Points_Vector points_on_Y(10); 
points_on_Y[0] = 0.0; points_on_Y[1] = 1.0; 
points_on_Y[2] = 2.5; points_on_Y[3] = 4.0; 
points_on_Y[4] = 6.0; points_on_Y[5] = 9.0; 
points_on_Y[6] = 12.; points_on_Y[7] = 14.; 
points_on_Y[8] = 18.; points_on_Y[9] = 20.; 

Histo2DVar *histo2 = new Histo2DVar( "Histo2DVar", points_on_X, points_on_Y ); 

Both the class names and type of vector used depends on whether transient or persistent histograms are involved.