ofstream fplot;
    fplot.open("Comparacion.plt", ios::trunc);
    fplot << "set title " << "\"" << "Compracion " << nombre1 << " vs. " << nombre2 << "\"" << endl;
    fplot << "set key top left vertical inside\n";
    fplot << "set grid\n";
    fplot << "set xlabel \"Talla (n)\" \n";
    fplot << "set ylabel \"Tiempo (ms)\" \n";
    fplot << "plot \"" "Comparacion.txt\" using 1:2 with lines title \"" << nombre1 << "\" , \"" << "Comparcion.txt\" using 1:3 with lines title \"" << nombre2 << "\"\n";
    fplot << "set terminal pdf\n";
    fplot << "set output \"comparacion.png\" \n";
    fplot << "replot\n";
    fplot << "pause 5 'Pulsa Enter para continuar...' \n";
    fplot.close();
    cout << "Grafica guardada en el fichero Comparacion.png" << endl;

    system("Comparacion.plt");