1. Removed obsolete test functions
[u/mrichter/AliRoot.git] / STAT / Macros / pdfCompare.C
CommitLineData
8a8f8274 1void pdfCompare(const Int_t method = 0, const int nstat = 40000)
2{
3// Compare interpolation methods.
4// method = 0 : Select COG method
5// method = 1 : Select INT method
6
7 const int bucket = nstat/100; //400;
8 const int nevals = 100;
9 Float_t *data[1];
10 Float_t data1[nstat];
11 for(int istat=0; istat<nstat; istat++) data1[istat] = gRandom->Gaus();
12 data[0] = &data1[0];
13
14 TLegend *leg = new TLegend(0.7157258,0.8280255,0.9637097,0.9596603);
15 leg->SetBorderSize(1);
16 TF1 *f=new TF1("f1", "gaus(0);x;f(x)", -5., 5.);
17 f->SetLineWidth(1);
18 f->SetLineColor(2);
19 f->SetParameter(0, 1.);
20 f->SetParameter(1, 0.);
21 f->SetParameter(2, 1.);
22 f->SetParameter(0, 1./f->Integral(-10., 10.));
23 f->Draw(); leg->AddEntry(f, "model", "l");
24
25
26 Float_t cog, val, val_err;
27 Double_t x, chi2, CHI2, result, err;
28 Int_t npoints;
29 TKDPDF pdf(nstat, 1, bucket, data);
30 pdf.SetInterpolationMethod(method);
31 pdf.SetStore();
32 pdf.SetAlpha(1.);
33 Float_t *bounds;// = in.GetBoundary(0);
34 Double_t dx = 10./nevals;
35
36 TGraph *gRE = new TGraph(npoints);
37 gRE->SetMarkerStyle(4);
38 gRE->SetMarkerColor(4);
39 gRE->SetLineColor(4);
40
41 // do a preevaluation for INT method on COG points
42 Float_t *pcog;
43 for(int icog=0; icog<pdf.GetNTNodes(); icog++){
44 pdf.GetCOGPoint(icog, pcog, val, val_err);
45 x = pcog[0];
46 chi2 = pdf.Eval(&x, result, err);
47 }
48 //pdf.GetStatus();
49
50 TGraphErrors *gINT = new TGraphErrors(npoints);
51 gINT->SetMarkerStyle(7);
52 x = 5.-dx/2.;
53 CHI2 = 0.; npoints = 0;
54 for(int ip=0; ip<nevals; ip++){
55 chi2 = pdf.Eval(&x, result, err);
56 gINT->SetPoint(ip, x, result);
57 gINT->SetPointError(ip, 0., err);
58 gRE->SetPoint(ip, x, .01*err/TMath::Abs(result));
59 if(TMath::Abs(x)<2.){
60 CHI2 += (result - f->Eval(x))*(result - f->Eval(x))/err/err;
61 npoints++;
62 }
63 x -= dx;
64 }
65 gINT->Draw("p"); leg->AddEntry(gINT, Form("interpolation [%s]", method ? "INT" : "COG"), "pl");
66
67 gRE->Draw("pl"); leg->AddEntry(gRE, "1% relative errors", "pl");
68 CHI2 /= npoints;
69 printf("chi2(%d) = %f\n", npoints, CHI2);
70
71 leg->Draw();
72}
73
74
75