ROOT Analysis FrameWork (II) Basics. Qipeng Hu March 22, 2015

Transcription

1 ROOT Analysis FrameWork (II) Basics Qipeng Hu March 22, 2015

2 Webpage of this tutorial 2

3 Outline Introduction to Linux command line Introduction to text editor Plotting a function Simple histogram Hand-on exercises 3

4 Linux 根 目录 4

5 Command line Useful commands: pwd 显 示当前 目录 ls [-la] 显 示当前 目录中的 文件 cd [dir] 进 入指定 目录 mkdir MyDir 新建名为 MyDir 的 目录 rm foo 删除 文件 foo cp foo1 foo2 复制 mv foo1 foo2 移动 man [command] 查看指令说明 ps 显 示进程./foo 执 行 文件 ctrl-c 中断前台进程 ctrl-d EOF chmod 755 foo 更改 文件属性 > 重定向 ls > files_in_dir.txt 通道 ps aux grep root drwxr- xr- x 4 qhu staff 136 Feb 20 20:18 cmake drwxr- xr- x 78 qhu staff 2652 Mar 2 22:26 config - rw- r- - r- - 1 qhu staff Mar 3 11:44 config.log - rw- r- - r- - 1 qhu staff 16 Mar 3 11:44 config.status - rwxr- xr- x 1 qhu staff Feb 20 20:18 configure 5 d rwx r-x r-x 目录 自 己组群其他 用户 r 读,w 写,x 执 行 1:x 2:w 4:r 5:rx 7:rwx

6 Simple Shell script HelloWorld.sh #!/bin/bash # Simple test shell script echo "What's your name?" read PERSON echo "" echo "Hello, $PERSON!" echo - e "You know what?\ni can count:" for i in do echo "$i" done 6

7 Choose your favorite editor 打开 文件 vi foo.c War of editors 两种模式 : 输 入 / 命令 i 进 入输 入模式, esc 进 入模式 保存 文件 :w 退出 vim :q 退出并保存 :wq 退出不保存 :q! 可在 ~/ 目录下创建.vimrc 文件配置语法 高亮, 背景颜 色, 自动缩进 7

8 ROOT command line cd $ROOTSYS/tutorials/tree/ root - l root [0].L basic.c root [1].x basic.c root [2].? root [3].q root [4].qqq // load basic.c // load and execute basic.c // list all the CINT command // quite ROOT // REALLY quite ROOT root [5].! ls root [6].! cat basic.c // Shell commands start with.! root [7] TBrowser *b = new TBrowser() 8

9 Plotting a function sin(x)/x y y= sin(x) x 0.6 cd ~/ mkdir testarea cd testarea root - l root [0] TF1* f1 = new TF1("f1","sin(x)/x",0,10) root [1] f1- >Draw() File->Save->Canvas1.root root - l Canvas_1.root root [1].ls root [2] TBrowser b x 9

10 Plotting a function (II) void func1() { // output root file named macro_out.root TFile* fout = new TFile("macro_out.root","RECREATE"); // Create a TF1 object f1 TF1* f1 = new TF1("func1","sin(x)/x",0,10); // Set line color&style and titles f1- >SetLineColor(4); f1- >SetLineStyle(2); f1- >GetXaxis()- >SetTitle("x"); f1- >GetYaxis()- >SetTitle("y"); // Create a TLatex object TLatex* Tl = new TLatex(8,.8,"y = #frac{sin(x)}{x}"); // Create a TCanvas object TCanvas* c1 = new TCanvas(); f1- >Draw(); Tl- >Draw("SAME"); // Save TCanvas object to output file and clear heap c1- >Write(); fout- >Close(); delete f1; delete c1; delete Tl; delete fout; } 10 Compiler vs. Interpreter Interpreter runs instruction by instruction, while compiler turns the entire program into machine language before executing. Macro can be executed by interpreter. Main function name must be the same with macro name. Preprocessor #include is not necessary. To run macro func1.c: root - l func1.c or root - l root [0].x func1.c

11 Plotting a function (III) // Create a TF1 object f1 TF1* f1 = new TF1("func1","sin(x)/x",0,10); // Set line color&style and titles f1- >SetLineColor(4); f1- >SetLineStyle(2); f1- >GetXaxis()- >SetTitle("x"); f1- >GetYaxis()- >SetTitle( y"); f1- >Draw(); A look at C++ interface 3 sources of memory allocation: - Static memory allocation - Stack - Dynamic memory allocation (heap) root [0] TF1* f1 = new TF1("func1","sin(x)/x") root [1] f1- >Draw() 11

12 Plotting a function (IV) #include "TFile.h" #include "TF1.h" #include "TLatex.h" #include "TAxis.h" #include "TCanvas.h" int main() { // output root file named exe_out.root } Plot a function with C++ compiler TFile* fout = new TFile("exe_out.root","RECREATE"); // Create a TF1 object f1 TF1* f1 = new TF1("func1","sin(x)/x",0,10); // Set line color&style and titles f1- >SetLineColor(4); f1- >SetLineStyle(2); f1- >GetXaxis()- >SetTitle("x"); f1- >GetYaxis()- >SetTitle("y"); // Create a TLatex object TLatex* Tl = new TLatex(8,.8,"y = #frac{sin(x)}{x}"); // Create a TCanvas object TCanvas* c1 = new TCanvas(); f1- >Draw(); Tl- >Draw("SAME"); // Save TCanvas object to output file and clear heap c1- >Write(); fout- >Close(); delete f1; delete c1; delete Tl; delete fout; return 0; 12 CXX=`${ROOTSYS}/bin/root- config - - cxx` CXXFLAGS=`${ROOTSYS}/bin/root- config - - cflags` LDFLAGS=`${ROOTSYS}/bin/root- config - - ldflags` ROOTLIBS=`${ROOTSYS}/bin/root- config - - libs` func2.exe: $(CXX) $(CXXFLAGS) - o $@ func2.c $(ROOTLIBS) clean: - rm - rf func2.exe root-config: Root utility for your Makefiles more details: man root- config To run with compiler: make./func2.exe

13 Simple histogram void hist1() { // Create a 1D histogram object of floats(f) TH1F* h1 = new TH1F("h1","histogram",100,- 5,5); // Call the FillRandom method which fills the histogram with gaus- distributed evets h1- >FillRandom("gaus",10000); TCanvas* c1 = new TCanvas(); c1- >cd(); h1- >Draw(); TH2F* h2 = new TH2F("h2","2D histogram",100,- 5.,5.,100,0.,1.); TF2* func = new TF2("gaus2","xgaus(0)*ygaus(3)"); func- >SetParameters(1.,0.,1., // Set the parameter of the first gaussian to N=1, mean=0, sigma=1. 1.,0.5,0.1); // Set the parameter of the second gaussian to N=1, mean=0.5, sigma=0.1 h2- >FillRandom("gaus2",100000); TCanvas* c2 = new TCanvas(); } c2- >cd(); gstyle- >SetPalette(53); h2- >Draw("surf"); //"LEGO2Z" 13 More Draw options of histogram: THistPainter

14 Thanks

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