blow.C

void Blow(TH1 *h1, Axis_t mn, Axis_t mx, Char_t *axis = "X")
{
        if (axis == "X") {
                h1->GetXaxis()->SetRange(h1->GetXaxis()->FindBin(mn),
                                         h1->GetXaxis()->FindBin(mx));
        } else {
                h1->GetYaxis()->SetRange(h1->GetYaxis()->FindBin(mn),
                                         h1->GetYaxis()->FindBin(mx));
        }
}