Function drawSingle

(pad, histos, styles=_defaultStyles,
               nrows=1,
               xtitle=None, ytitle=None,
               drawOpt="HIST",
               legendDx=0, legendDy=0, legendDw=0, legendDh=0,
               xmin=None, ymin=0, xmax=None, ymax=None, xlog=False, ylog=False,
               xgrid=True, ygrid=True,
               ratio=False, ratioYmin=0.5, ratioYmax=1.5, ratioYTitle=plotting._ratioYTitle, ratioFactor=1.25)