mass.cpp

void mass() {
    TH1F *h1= new TH1F("masse"," masse", 100,0,150) ;

    FILE *fp = fopen ("mass.txt", "r");
    float inv_mass = 0;
    while (fscanf(fp, "%e", &inv_mass) > 0)
    {
        printf("m = %.3f\n", inv_mass);
        h1->Fill(inv_mass);
    }
 h1-> Draw();
}