避免上述问题的方法是建立分析代码类(class ana)，该类继承由MakeClass生成的类(class tracking)。这样可不改动原来的类，并将用户分析代码与原来的代码分开，互不干扰。
主目录: ./tracking
./tracking
- main.cpp - 主程序
- Makefile -编译方法
./tracking/include/
- tracking.h - MakeClass 生成的头文件
- ana.h - 用户分析头文件
./tracking/src/
- tracking.C -MakeClass生成的源文件
- ana.cpp 用户分析源文件
root -l f8ppac001.root
[0] tree->MakeClass("tracking")
生成 tracking.h 和 tracking.C
#include <iostream>
#include <TFile.h>
#include <TTree.h>
#include <TString.h>
#include "ana.h" //用户代码头文件
using namespace std;
int main(int argc, char** argv)
{
if(argc !=2) {
cout<<"Usage: ./"<<argv[0]<<" run_number "<<endl;
return -1;
}
int run_number = atoi(argv[1]);
TString InputPath, OutputPath, infile, outfile;
InputPath = "./";
OutputPath = "./";
infile.Form("%sf8ppac%03d.root", InputPath.Data(), run_number);
outfile.Form("%sout%03d.root", OutputPath.Data(), run_number);
//input
TFile *ipf = new TFile(infile);
if(!ipf->IsOpen()) {
cout<<"Cannot open input file: "<<infile<<endl;
return -1;
}
TTree *ipt = (TTree*)ipf->Get("tree");
//output
TFile *opf = new TFile(outfile,"RECREATE");
TTree *opt = new TTree("tree","ppac tracking");
cout << "Inputfile: "<<infile.Data() << endl;
cout << "Outputfile: "<<outfile.Data() << endl;
//
ana *tk = new ana(run_number,ipt);
tk->Analysis(opt); //等价于原Loop函数
//
ipf->Close();
opf->Close();
return 1;
}
#ifndef ana_h
#define ana_h
#include <TH2.h>
#include <iostream>
#include "tracking.h" //包含基类头文件
using namespace std;
class ana : public tracking //从tracking类中继承其成员变量和成员函数
{
public:
int run; //run_number
Double_t xx[3], xz[3], yy[3], yz[3];//1A,2A,3
Double_t p2bx, p2by;//2B x-y
Double_t dx[3], dy[3];
Double_t tx, ty;//target pos
Double_t c2nx, c2ny;//chi2/ndf for xfit,yfit
TH2D *htf8x, *htf8y, *htar;
//构造函数：将传入的tree传递给tracking基类，完成初始化
ana(int run_number, TTree* tree): tracking(tree), run(run_number) {} //tracking = tree; run=run_number;
virtual ~ana() {};
virtual void Analysis(TTree *tree);//分析函数，作用等价于原Loop函数
virtual void SetOutBranch(TTree *tree);
virtual void TrackInit();
virtual void SetTrace(TH2D *h, Double_t k, Double_t b, Int_t min, Int_t max);
};
#endif
#include <TH2.h>
#include <TStyle.h>
#include <TCanvas.h>
#include <TF1.h>
#include <TFitResult.h>
#include <TGraph.h>
#include "ana.h"
using namespace std;
void ana::SetOutBranch(TTree *tree)
{
//measured pos
tree->Branch("xx",&xx,"xx[3]/D");//1A,2A,3
tree->Branch("xz",&xz,"xz[3]/D");
tree->Branch("yy",&yy,"yy[3]/D");
tree->Branch("yz",&yz,"yz[3]/D");
...
}
void ana::TrackInit()
{
tx = -999;
ty = -999;
//1A
xx[0] = PPACF8[0][0];
yy[0] = PPACF8[0][1];
xz[0] = PPACF8[0][2];
yz[0] = PPACF8[0][3];
...
}
void ana::SetTrace(TH2D *h, Double_t k, Double_t b, Int_t min, Int_t max){
if(h == 0) return;
if(min >= max) return;
...
}
void ana::Analysis(TTree *tree)
{
TH2D *htf8x = new TH2D("htf8x","x trace by ppac", 2200, -2000, 200, 300, -150, 150);
TH2D *htf8y = new TH2D("htf8y","y trace by ppac", 2200, -2000, 200, 300, -150, 150);
TH2D *htar = new TH2D("htar","distribution on target", 100, -50, 50, 100, -50, 50);
SetOutBranch(tree);
if (fChain == 0) return;
Long64_t nentries = fChain->GetEntriesFast();
Long64_t nbytes = 0, nb = 0;
for (Long64_t jentry=0; jentry<nentries;jentry++) {
Long64_t ientry = LoadTree(jentry);
if (ientry < 0) break;
nb = fChain->GetEntry(jentry); nbytes += nb;
...
}
...
}