10 /// \file LandauTest.C
12 class TLandauMean: public TObject {
14 void Init(Int_t n, Float_t mean, Float_t sigma); // initial parameters
15 void Gener(); // gener sample
19 Int_t fNSample; // number of samples
20 Float_t fLMean; // landau mean
21 Float_t fLSigma; // landau sigma
23 Float_t fTM_0_6[3]; // truncated method - first 3 momenta
24 Float_t fTM_0_7[3]; // truncated method - first 3 momenta
25 Float_t fTM_0_8[3]; // truncated method - first 3 momenta
26 Float_t fTM_0_10[3]; // truncated method - first 3 momenta
28 Float_t fLM_0_6[3]; // truncated log. method - first 3 momenta
29 Float_t fLM_0_7[3]; // truncated log. method - first 3 momenta
30 Float_t fLM_0_8[3]; // truncated log. method - first 3 momenta
31 Float_t fLM_0_10[3]; // truncated log. method - first 3 momenta
33 Float_t fMedian3; // median 3 value
35 Float_t Moment3(Float_t sum1, Float_t sum2, Float_t sum3, Int_t n, Float_t m[3]);
36 ClassDef(TLandauMean,1)
43 void TLandauMean::Init(Int_t n, Float_t mean, Float_t sigma)
52 Float_t TLandauMean::Moment3(Float_t sumi1, Float_t sumi2, Float_t sumi3, Int_t sum, Float_t m[3])
56 // m3 = (sumi3-3*pos*sumi2+3*pos*pos*sumi-pos*pos*pos*sum)/sum;
57 Float_t pos = sumi1/sum;
59 m[1] = sumi2/sum-pos*pos;
61 printf("pici pici\n");
64 m[1] = TMath::Sqrt(m[1]);
65 m3 = (sumi3-3*pos*sumi2+3*pos*pos*sumi1-pos*pos*pos*sum)/sum;
66 Float_t sign = m3/TMath::Abs(m3);
67 m3 = TMath::Power(sign*m3,1/3.);
74 void TLandauMean::Gener()
78 Float_t * buffer = new Float_t[fNSample];
80 for (Int_t i=0;i<fNSample;i++) {
81 buffer[i] = gRandom->Landau(fLMean,fLSigma);
82 if (buffer[i]>1000) buffer[i]=1000;
85 Int_t *index = new Int_t[fNSample];
86 TMath::Sort(fNSample,buffer,index,kFALSE);
89 Float_t median = buffer[index[fNSample/3]];
91 Float_t sum06[4] = {0.,0.,0.,0.};
92 Float_t sum07[4] = {0.,0.,0.,0.};
93 Float_t sum08[4] = {0.,0.,0.,0.};
94 Float_t sum010[4] = {0.,0.,0.,0.};
96 Float_t suml06[4] = {0.,0.,0.,0.};
97 Float_t suml07[4] = {0.,0.,0.,0.};
98 Float_t suml08[4] = {0.,0.,0.,0.};
99 Float_t suml010[4] = {0.,0.,0.,0.};
102 for (Int_t i =0; i<fNSample; i++){
103 Float_t amp = buffer[index[i]];
104 Float_t lamp = median*TMath::Log(1.+amp/median);
108 sum06[2]+= amp*amp*amp;
111 suml06[1]+= lamp*lamp;
112 suml06[2]+= lamp*lamp*lamp;
119 sum07[2]+= amp*amp*amp;
122 suml07[1]+= lamp*lamp;
123 suml07[2]+= lamp*lamp*lamp;
129 sum08[2]+= amp*amp*amp;
132 suml08[1]+= lamp*lamp;
133 suml08[2]+= lamp*lamp*lamp;
139 sum010[2]+= amp*amp*amp;
142 suml010[1]+= lamp*lamp;
143 suml010[2]+= lamp*lamp*lamp;
151 Moment3(sum06[0],sum06[1],sum06[2],sum06[3],fTM_0_6);
152 Moment3(sum07[0],sum07[1],sum07[2],sum07[3],fTM_0_7);
153 Moment3(sum08[0],sum08[1],sum08[2],sum08[3],fTM_0_8);
154 Moment3(sum010[0],sum010[1],sum010[2],sum010[3],fTM_0_10);
157 Moment3(suml06[0],suml06[1],suml06[2],suml06[3],fLM_0_6);
158 Moment3(suml07[0],suml07[1],suml07[2],suml07[3],fLM_0_7);
159 Moment3(suml08[0],suml08[1],suml08[2],suml08[3],fLM_0_8);
160 Moment3(suml010[0],suml010[1],suml010[2],suml010[3],fLM_0_10);
162 fLM_0_6[0] = (TMath::Exp(fLM_0_6[0]/median)-1.)*median;
163 fLM_0_7[0] = (TMath::Exp(fLM_0_7[0]/median)-1.)*median;
164 fLM_0_8[0] = (TMath::Exp(fLM_0_8[0]/median)-1.)*median;
165 fLM_0_10[0] = (TMath::Exp(fLM_0_10[0]/median)-1.)*median;
171 void GenerLandau(Int_t nsamples)
173 TLandauMean * landau = new TLandauMean;
174 TFile f("Landau.root","recreate");
175 TTree * tree = new TTree("Landau","Landau");
176 tree->Branch("Landau","TLandauMean",&landau);
178 for (Int_t i=0;i<nsamples;i++){
179 Int_t n = 20 + Int_t(gRandom->Rndm()*150);
180 Float_t mean = 40. +gRandom->Rndm()*50.;
181 Float_t sigma = 5. +gRandom->Rndm()*15.;
182 landau->Init(n, mean, sigma);
195 TH1F * LandauTest(Float_t meano, Float_t sigma, Float_t meanlog0, Int_t n,Float_t ratio)
197 /// test for different approach of de dx resolution
198 /// meano, sigma - mean value of Landau distribution and sigma
199 /// meanlog0 - scaling factor for logarithmic mean value
200 /// n - number of used layers
201 /// ratio - ratio of used amplitudes for truncated mean
204 TCanvas * pad = new TCanvas("Landau test");
206 TH1F * h1 = new TH1F("h1","Logarithmic mean",300,0,4*meano);
207 TH1F * h2 = new TH1F("h2","Logarithmic amplitudes",300,0,8*meano);
208 TH1F * h3 = new TH1F("h3","Mean",300,0,4*meano);
209 TH1F * h4 = new TH1F("h4","Amplitudes",300,0,8*meano);
211 for(Int_t j=0;j<10000;j++){
212 //generate sample and sort it
213 Float_t * buffer = new Float_t[n];
214 Float_t * buffer2= new Float_t[n];
216 for (Int_t i=0;i<n;i++) {
217 buffer[i] = gRandom->Landau(meano,sigma);
218 buffer2[i] = buffer[i];
221 for (Int_t i=1;i<n-1;i++) {
222 buffer[i] = buffer2[i]*1.0+ buffer2[i-1]*0.0+ buffer2[i+1]*0.0;
223 buffer[i] = TMath::Min(buffer[i],1000.);
225 Int_t *index = new Int_t[n];
226 TMath::Sort(n,buffer,index,kFALSE);
233 for (Int_t i=0;i<n*ratio;i++) {
234 if (buffer[index[i]]<1000.){
235 Float_t amp = meanlog0*TMath::Log(1+buffer[index[i]]/meanlog0);
245 Float_t meanlog =meanlog0;
246 for (Int_t i=0;i<n*ratio;i++) {
247 if (buffer[index[i]]<1000.){
248 Float_t amp = meanlog*TMath::Log(1.+buffer[index[i]]/(meanlog));
250 sum2+=buffer[index[i]];
253 h4->Fill(buffer[index[i]]);
257 mean = (TMath::Exp(mean/meanlog)-1)*meanlog;
258 Float_t mean2 = sum2/used;
259 //mean2 = (mean+mean2)/2.;