用root程序读取ntuple文件的信息时(root -l root_scr ipt.cxx)，需要此类型的画图脚本。输入存储信息的.root文件，取出指定tree下的leaf信息，画在一维直方图上，调整cut，不同的输入间图形对比，看图形形状的变化是否合理，进而解决问题。注：本程序在相关领域较实用，基本的东西都有，易于理解，借此入门，举一反三。-When reading information ntuple program file with the root (root-l root_scr ipt.cxx), you require this type of drawing scr ipts. Enter to store information .root file, remove the leaf information specified under the tree, painted on a one-dimensional histogram, adjust the cut, the graphical comparison between different input to see whether reasonable changes in pattern shape, and then solve the problem. Note: This program more practical in related fields, the basic things are easy to understand, thereby getting started, learn by analogy.