void test_tgraph() {
    TGraph MeV_to_cm("alphas_in_250torr_mix_filtered.txt","%lf %*lf %lf");
    TGraph cm_to_MeV(MeV_to_cm.GetN(), MeV_to_cm.GetY(), MeV_to_cm.GetX());

    MeV_to_cm.Draw("AL");
    while(gPad->WaitPrimitive());
    cm_to_MeV.Draw("AL");
    gPad->Modified(); gPad->Update();
    while(gPad->WaitPrimitive());

    double e=6.0,L=4.0;
    while(e>5.0) {
        double temp = MeV_to_cm.Eval(e)-L;
        std::cout << "If we detect an alpha at " << e << " MeV, covering a path of " << L << " cm, " << cm_to_MeV.Eval(MeV_to_cm.Eval(e)-L) << " MeV is its original energy " << L << " cm prior" << std::endl;
        e-=0.05;
    }
}