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Reference Guide
h1analysisProxy.C
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1/// \file
2/// \ingroup tutorial_tree
3/// Example of analysis class for the H1 data using code generated by MakeProxy.
4///
5/// This file uses 4 large data sets from the H1 collaboration at DESY Hamburg.
6/// One can access these data sets (277 MBytes) from the standard Root web site
7/// at: [https://root.cern.ch/files/h1/](https://root.cern.ch/files/h1/)
8/// The Physics plots below generated by this example cannot be produced when
9/// using smaller data sets.
10///
11/// There are several ways to analyze data stored in a Root Tree
12/// - Using TTree::Draw: This is very convenient and efficient for small tasks.
13/// A TTree::Draw call produces one histogram at the time. The histogram
14/// is automatically generated. The selection expression may be specified
15/// in the command line.
16///
17/// - Using the TTreeViewer: This is a graphical interface to TTree::Draw
18/// with the same functionality.
19///
20/// - Using the code generated by TTree::MakeClass: In this case, the user
21/// creates an instance of the analysis class. They have the control over
22/// the event loop and he can generate an unlimited number of histograms.
23///
24/// - Using the code generated by TTree::MakeSelector. Like for the code
25/// generated by TTree::MakeClass, the user can do complex analysis.
26/// However, they cannot control the event loop. The event loop is controlled
27/// by TTree::Process called by the user. This solution is illustrated
28/// by the current code. The advantage of this method is that it can be run
29/// in a parallel environment using PROOF (the Parallel Root Facility).
30///
31/// A chain of 4 files (originally converted from PAW ntuples) is used
32/// to illustrate the various ways to loop on Root data sets.
33/// Each data set contains a Root Tree named "h42"
34///
35/// h1analysProxy.C can be used either via TTree::Draw:
36/// ~~~{.cpp}
37/// h42->Draw("h1analysisProxy.C");
38/// ~~~
39/// or it can be used directly with TTree::MakeProxy, for example to generate a
40/// shared library. TTree::MakeProxy will generate a TSelector skeleton that
41/// include h1analysProxy.C:
42/// ~~~{.cpp}
43/// h42->MakeProxy("h1sel","h1analysisProxy.C");
44/// ~~~
45/// This produces one file: h1sel.h which does a #include "h1analysProxy.C"
46/// The h1sel class is derived from the Root class TSelector and can then
47/// be used as:
48/// ~~~{.cpp}
49/// h42->Process("h1sel.h+");
50/// ~~~
51///
52/// The following members functions are called by the TTree::Process functions.
53/// - **h1analysProxy_Begin()**: Called every time a loop on the tree starts.
54/// a convenient place to create your histograms.
55///
56/// - **h1analysProxy_Notify()**: This function is called at the first entry of a new Tree
57/// in a chain.
58/// - **h1analysProxy_Process()**: called to analyze each entry.
59///
60/// - **h1analysProxy_Terminate()**: called at the end of a loop on a TTree.
61/// a convenient place to draw/fit your histograms.
62///
63/// To use this file, try the following session
64/// ~~~{.cpp}
65/// Root > gROOT->Time(); ///will show RT & CPU time per command
66/// ~~~
67/// ### Case A: Create a TChain with the 4 H1 data files
68/// The chain can be created by executed the short macro h1chain.C below:
69/// ~~~{.cpp}
70/// {
71/// TChain chain("h42");
72/// chain.Add("$H1/dstarmb.root"); /// 21330730 bytes 21920 events
73/// chain.Add("$H1/dstarp1a.root"); /// 71464503 bytes 73243 events
74/// chain.Add("$H1/dstarp1b.root"); /// 83827959 bytes 85597 events
75/// chain.Add("$H1/dstarp2.root"); /// 100675234 bytes 103053 events
76/// ///where $H1 is a system symbol pointing to the H1 data directory.
77/// }
78/// ~~~
79///
80/// ### Case B: Loop on all events
81/// ~~~{.cpp}
82/// Root > chain.Draw("h1analysisProxy.C")
83/// ~~~
84///
85/// ### Case C: Same as B, but in addition fill the event list with selected entries.
86/// The event list is saved to a file "elist.root" by the Terminate function.
87/// To see the list of selected events, you can do elist->Print("all").
88/// The selection function has selected 7525 events out of the 283813 events
89/// in the chain of files. (2.65 per cent)
90/// ~~~{.cpp}
91/// Root > chain.Draw("h1analysisProxy.C","","fillList")
92/// ~~~
93/// ### Case D: Process only entries in the event list
94/// The event list is read from the file in elist.root generated by step C
95/// ~~~{.cpp}
96/// Root > chain.Draw("h1analysisProxy.C","","useList")
97/// ~~~
98///
99/// The commands executed with the 3 different methods B,C and D
100/// produce two canvases shown below:
101/// begin_html <a href="gif/h1analysis_dstar.gif" >the Dstar plot</a> end_html
102/// begin_html <a href="gif/h1analysis_tau.gif" >the Tau D0 plot</a> end_html
103///
104/// \macro_code
105///
106/// \author Philippe Canal from original h1analysis.C by Rene Brun
107
108TEntryList *elist;
109Bool_t useList, fillList;
110TH1F *hdmd;
111TH2F *h2;
112
113
114void h1analysisProxy_Begin(TTree *tree)
115{
116// function called before starting the event loop
117// -it performs some cleanup
118// -it creates histograms
119// -it sets some initialisation for the event list
120
121 //print the option specified in the Process function.
122 TString option = GetOption();
123 printf("Starting (begin) h1analysis with process option: %s\n",option.Data());
124
125 //process cases with event list
126 fillList = kFALSE;
127 useList = kFALSE;
128 if (fChain) fChain->SetEntryList(0);
129 delete gDirectory->GetList()->FindObject("elist");
130
131 // case when one creates/fills the event list
132 if (option.Contains("fillList")) {
133 fillList = kTRUE;
134 elist = new TEntryList("elist","H1 selection from Cut");
135 // Add to the input list for processing in PROOF, if needed
136 if (fInput) {
137 fInput->Add(new TNamed("fillList",""));
138 fInput->Add(elist);
139 }
140 } else elist = 0;
141
142 // case when one uses the event list generated in a previous call
143 if (option.Contains("useList")) {
144 useList = kTRUE;
145 if (fInput) {
146 tree->SetEntryList(elist);
147 TFile f("elist.root");
148 elist = (TEntryList*)f.Get("elist");
149 if (elist) elist->SetDirectory(0); //otherwise the file destructor will delete elist
150 } else {
151 // Option "useList" not supported in PROOF directly
152 Warning("Begin", "option 'useList' not supported in PROOF - ignoring");
153 Warning("Begin", "the entry list must be set on the chain *before* calling Process");
154 }
155 }
156}
157
158
159void h1analysisProxy_SlaveBegin(TTree *tree)
160{
161// function called before starting the event loop
162// -it performs some cleanup
163// -it creates histograms
164// -it sets some initialisation for the entry list
165
166 //initialize the Tree branch addresses
167 Init(tree);
168
169 //print the option specified in the Process function.
170 TString option = GetOption();
171 printf("Starting (slave) h1analysis with process option: %s\n",option.Data());
172
173 //create histograms
174 hdmd = new TH1F("hdmd","dm_d",40,0.13,0.17);
175 h2 = new TH2F("h2","ptD0 vs dm_d",30,0.135,0.165,30,-3,6);
176
177 fOutput->Add(hdmd);
178 fOutput->Add(h2);
179
180 //process cases with entry list
181 fillList = kFALSE;
182 useList = kFALSE;
183
184 // case when one creates/fills the entry list
185 if (option.Contains("fillList")) {
186 fillList = kTRUE;
187 // Get the list
188 if (fInput) {
189 if ((elist = (TEntryList *) fInput->FindObject("elist")))
190 // Need to clone to avoid problems when destroying the selector
191 elist = (TEntryList *) elist->Clone();
192 }
193 if (elist)
194 fOutput->Add(elist);
195 else
196 fillList = kFALSE;
197 } else elist = 0;
198
199 // case when one uses the entry list generated in a previous call
200 if (option.Contains("useList")) {
201 useList = kTRUE;
202 TFile f("elist.root");
203 elist = (TEntryList*)f.Get("elist");
204 if (elist) elist->SetDirectory(0); //otherwise the file destructor will delete elist
205 if (tree) tree->SetEntryList(elist);
206 else {
207 // Option "useList" not supported in PROOF directly
208 Warning("Begin", "option 'useList' not supported in PROOF - ignoring");
209 Warning("Begin", "the entry list must be set on the chain *before* calling Process");
210 }
211 }
212
213}
214
215Double_t h1analysisProxy() {
216 return 0;
217}
218
219
220Bool_t h1analysisProxy_Process(Long64_t entry)
221{
222// entry is the entry number in the current Tree
223// Selection function to select D* and D0.
224
225 //in case one entry list is given in input, the selection has already been done.
226 if (!useList) {
227
228 float f1 = md0_d;
229 float f2 = md0_d-1.8646;
230 bool test = TMath::Abs(md0_d-1.8646) >= 0.04;
231 if (gDebug>0) fprintf(stderr,"entry #%lld f1=%f f2=%f test=%d\n",
232 fChain->GetReadEntry(),f1,f2,test);
233
234 if (TMath::Abs(md0_d-1.8646) >= 0.04) return kFALSE;
235 if (ptds_d <= 2.5) return kFALSE;
236 if (TMath::Abs(etads_d) >= 1.5) return kFALSE;
237
238 int cik = ik-1; //original ik used f77 convention starting at 1
239 int cipi = ipi-1; //original ipi used f77 convention starting at 1
240
241 f1 = nhitrp[cik];
242 f2 = nhitrp[cipi];
243 test = nhitrp[cik]*nhitrp[cipi] <= 1;
244 if (gDebug>0) fprintf(stderr,"entry #%lld f1=%f f2=%f test=%d\n",
245 fChain->GetReadEntry(),f1,f2,test);
246
247 if (nhitrp[cik]*nhitrp[cipi] <= 1) return kFALSE;
248 if (rend[cik] -rstart[cik] <= 22) return kFALSE;
249 if (rend[cipi]-rstart[cipi] <= 22) return kFALSE;
250 if (nlhk[cik] <= 0.1) return kFALSE;
251 if (nlhpi[cipi] <= 0.1) return kFALSE;
252 // fix because read-only
253 if (nlhpi[ipis-1] <= 0.1) return kFALSE;
254 if (njets < 1) return kFALSE;
255
256 }
257 // if option fillList, fill the event list
258 if (fillList) elist->Enter(entry);
259
260 //fill some histograms
261 hdmd->Fill(dm_d);
262 h2->Fill(dm_d,rpd0_t/0.029979*1.8646/ptd0_d);
263
264 return kTRUE;
265}
266
267
268
269void h1analysisProxy_SlaveTerminate()
270{
271 // nothing to be done
272 printf("Terminate (slave) h1analysis\n");
273}
274
275
276void h1analysisProxy_Terminate()
277{
278 printf("Terminate (final) h1analysis\n");
279
280 // function called at the end of the event loop
281
282 hdmd = dynamic_cast<TH1F*>(fOutput->FindObject("hdmd"));
283 h2 = dynamic_cast<TH2F*>(fOutput->FindObject("h2"));
284
285 if (hdmd == 0 || h2 == 0) {
286 Error("Terminate", "hdmd = %p , h2 = %p", hdmd, h2);
287 return;
288 }
289
290 //create the canvas for the h1analysis fit
291 gStyle->SetOptFit();
292 TCanvas *c1 = new TCanvas("c1","h1analysis analysis",10,10,800,600);
293 c1->SetBottomMargin(0.15);
294 hdmd->GetXaxis()->SetTitle("m_{K#pi#pi} - m_{K#pi}[GeV/c^{2}]");
295 hdmd->GetXaxis()->SetTitleOffset(1.4);
296
297 //fit histogram hdmd with function f5 using the log-likelihood option
298 TF1 *f5 = new TF1("f5",fdm5,0.139,0.17,5);
299 f5->SetParameters(1000000, .25, 2000, .1454, .001);
300 hdmd->Fit("f5","lr");
301
302 //create the canvas for tau d0
303 gStyle->SetOptFit(0);
304 gStyle->SetOptStat(1100);
305 TCanvas *c2 = new TCanvas("c2","tauD0",100,100,800,600);
306 c2->SetGrid();
307 c2->SetBottomMargin(0.15);
308
309 // Project slices of 2-d histogram h2 along X , then fit each slice
310 // with function f2 and make a histogram for each fit parameter
311 // Note that the generated histograms are added to the list of objects
312 // in the current directory.
313 TF1 *f2 = new TF1("f2",fdm2,0.139,0.17,2);
314 f2->SetParameters(10000, 10);
315 h2->FitSlicesX(f2,0,-1,1,"qln");
316 TH1D *h2_1 = (TH1D*)gDirectory->Get("h2_1");
317 h2_1->GetXaxis()->SetTitle("#tau[ps]");
318 h2_1->SetMarkerStyle(21);
319 h2_1->Draw();
320 c2->Update();
321 TLine *line = new TLine(0,0,0,c2->GetUymax());
322 line->Draw();
323
324 // Have the number of entries on the first histogram (to cross check when running
325 // with entry lists)
326 TPaveStats *psdmd = (TPaveStats *)hdmd->GetListOfFunctions()->FindObject("stats");
327 psdmd->SetOptStat(1110);
328 c1->Modified();
329
330 //save the entry list to a Root file if one was produced
331 if (fillList) {
332 elist = dynamic_cast<TEntryList*>(fOutput->FindObject("elist"));
333 if (elist) {
334 TFile efile("elist.root","recreate");
335 elist->Write();
336 } else {
337 Error("Terminate", "entry list requested but not found in output");
338 }
339 }
340}
#define f(i)
Definition: RSha256.hxx:104
const Bool_t kFALSE
Definition: RtypesCore.h:101
bool Bool_t
Definition: RtypesCore.h:63
double Double_t
Definition: RtypesCore.h:59
long long Long64_t
Definition: RtypesCore.h:80
const Bool_t kTRUE
Definition: RtypesCore.h:100
#define gDirectory
Definition: TDirectory.h:348
void Error(const char *location, const char *msgfmt,...)
Use this function in case an error occurred.
Definition: TError.cxx:187
void Warning(const char *location, const char *msgfmt,...)
Use this function in warning situations.
Definition: TError.cxx:231
Int_t gDebug
Definition: TROOT.cxx:592
R__EXTERN TStyle * gStyle
Definition: TStyle.h:412
virtual void SetTitleOffset(Float_t offset=1)
Set distance between the axis and the axis title.
Definition: TAttAxis.cxx:301
virtual void SetMarkerStyle(Style_t mstyle=1)
Set the marker style.
Definition: TAttMarker.h:40
The Canvas class.
Definition: TCanvas.h:23
A List of entry numbers in a TTree or TChain.
Definition: TEntryList.h:26
virtual void SetDirectory(TDirectory *dir)
Add reference to directory dir. dir can be 0.
virtual Bool_t Enter(Long64_t entry, TTree *tree=0)
Add entry #entry to the list.
Definition: TEntryList.cxx:625
1-Dim function class
Definition: TF1.h:213
virtual void SetParameters(const Double_t *params)
Definition: TF1.h:644
A ROOT file is a suite of consecutive data records (TKey instances) with a well defined format.
Definition: TFile.h:54
1-D histogram with a double per channel (see TH1 documentation)}
Definition: TH1.h:618
1-D histogram with a float per channel (see TH1 documentation)}
Definition: TH1.h:575
TAxis * GetXaxis()
Get the behaviour adopted by the object about the statoverflows. See EStatOverflows for more informat...
Definition: TH1.h:320
virtual TFitResultPtr Fit(const char *formula, Option_t *option="", Option_t *goption="", Double_t xmin=0, Double_t xmax=0)
Fit histogram with function fname.
Definition: TH1.cxx:3892
virtual Int_t Fill(Double_t x)
Increment bin with abscissa X by 1.
Definition: TH1.cxx:3350
TList * GetListOfFunctions() const
Definition: TH1.h:243
virtual void Draw(Option_t *option="")
Draw this histogram with options.
Definition: TH1.cxx:3073
2-D histogram with a float per channel (see TH1 documentation)}
Definition: TH2.h:251
Int_t Fill(Double_t)
Invalid Fill method.
Definition: TH2.cxx:358
virtual void FitSlicesX(TF1 *f1=0, Int_t firstybin=0, Int_t lastybin=-1, Int_t cut=0, Option_t *option="QNR", TObjArray *arr=0)
Project slices along X in case of a 2-D histogram, then fit each slice with function f1 and make a hi...
Definition: TH2.cxx:979
Use the TLine constructor to create a simple line.
Definition: TLine.h:22
virtual TObject * FindObject(const char *name) const
Find an object in this list using its name.
Definition: TList.cxx:578
The TNamed class is the base class for all named ROOT classes.
Definition: TNamed.h:29
virtual void SetTitle(const char *title="")
Set the title of the TNamed.
Definition: TNamed.cxx:164
virtual TObject * Clone(const char *newname="") const
Make a clone of an object using the Streamer facility.
Definition: TNamed.cxx:74
virtual Int_t Write(const char *name=0, Int_t option=0, Int_t bufsize=0)
Write this object to the current directory.
Definition: TObject.cxx:798
virtual void Draw(Option_t *option="")
Default Draw method for all objects.
Definition: TObject.cxx:197
The histogram statistics painter class.
Definition: TPaveStats.h:18
void SetOptStat(Int_t stat=1)
Set the stat option.
Definition: TPaveStats.cxx:306
Basic string class.
Definition: TString.h:136
const char * Data() const
Definition: TString.h:369
Bool_t Contains(const char *pat, ECaseCompare cmp=kExact) const
Definition: TString.h:624
void SetOptStat(Int_t stat=1)
The type of information printed in the histogram statistics box can be selected via the parameter mod...
Definition: TStyle.cxx:1589
void SetOptFit(Int_t fit=1)
The type of information about fit parameters printed in the histogram statistics box can be selected ...
Definition: TStyle.cxx:1541
A TTree represents a columnar dataset.
Definition: TTree.h:79
TLine * line
Double_t fdm5(Double_t *xx, Double_t *par)
Double_t fdm2(Double_t *xx, Double_t *par)
return c1
Definition: legend1.C:41
TF1 * f1
Definition: legend1.C:11
return c2
Definition: legend2.C:14
void Init(TClassEdit::TInterpreterLookupHelper *helper)
Definition: TClassEdit.cxx:154
Short_t Abs(Short_t d)
Definition: TMathBase.h:120
Definition: test.py:1
Definition: tree.py:1