Vector<Pointf> b_temp = {};
b_temp << Pointf(t_in, posBarre) << Pointf(t_fine, posBarre);
barre.Add(b_temp);

...

for(int i = 0; i < barre.size(); i++){

  ...

  scOee.AddSeries(barre[i]).NoMark().Stroke(30, t_color).Dash(LINE_SOLID).Legend(AsString(i));
}

Vector<Pointf> v_media_temp = {};
v_media_temp << Pointf(t_in, lista_ml_l[i].QuestaMLav.v_media ) << Pointf(t_fine, lista_ml_l[i].QuestaMLav.v_media);
vel_media.Add(v_media_temp);

...

for(int i = 0; i < vel_media.size(); i++)
{

  ...

  scOee.AddSeries(vel_media[i]).NoMark().Stroke(1, LtGreen).Dash(LINE_SOLID).Legend("vm"+AsString(i));
}