Script to get # of dead channels from OCDB
[u/mrichter/AliRoot.git] / FMD / scripts / VA1Response.C
CommitLineData
bf000c32 1//____________________________________________________________________
d389af40 2//
a1f80595 3// $Id$
4//
d389af40 5// Script to try to fit the reponse function of the VA1 signals, based
6// on a finite number of ALTRO samples.
7//
9b48326f 8/** Make Va1 response
9 @param n
10 @param B
11 @param dc
12 @param errors
13 @ingroup simple_script
14*/
d389af40 15void
16VA1Response(Int_t n=2, Float_t B=5, Float_t dc=.01, Bool_t errors=kFALSE)
17{
18
19 TF1* response = new TF1("response", "[0] * (1 - exp(-[1] * x))", 0, 1.4);
20 response->SetParameters(1, B);
21 response->SetParNames("A", "B");
22 response->SetLineColor(2);
23
24 TF1* fit = new TF1("fit", "[0] * (1 - exp(-[1] * x))", 0, 1);
25 fit->SetParameters(.5, B/2);
26 fit->SetParNames("A", "B");
27 fit->SetLineColor(3);
28
29 TGraph* graph = 0;
30 if (errors) graph = new TGraphErrors(n);
31 else graph = new TGraph(n);
32 for (Int_t i = 0; i < n; i++) {
33 Float_t t = Float_t(i + 1) / n;
34 Float_t c = gRandom->Gaus(response->Eval(t), dc);
35 graph->SetPoint(i, t, c);
36 if (errors) ((TGraphErrors*)graph)->SetPointError(i, 0, dc);
37 }
38
39 response->Draw();
40 response->GetHistogram()->GetYaxis()->SetRangeUser(0, 1.4);
41 response->GetHistogram()->GetXaxis()->SetRangeUser(0, 1.4);
42 graph->Draw("P*");
43 TString fitOpt("E");
44 if (!errors) fitOpt.Append("W");
45 graph->Fit("fit", fitOpt.Data());
46 graph->Fit("fit", fitOpt.Data());
47
48 std::cout << "Chi^2/NDF = " << fit->GetChisquare() << "/" << fit->GetNDF()
49 << " = " << std::flush;
50 if (fit->GetNDF() == 0)
51 std::cout << " undefined!" << std::endl;
52 else
53 std::cout << (fit->GetChisquare() / fit->GetNDF()) << std::endl;
54 std::cout << "f(t) = "
55 << fit->GetParameter(0) << "+/-" << fit->GetParError(0)
56 << " * (1 - exp("
57 << fit->GetParameter(1) << "+/-" << fit->GetParError(1)
58 << " * t))" << std::endl;
59}
a1f80595 60//____________________________________________________________________
61//
62// EOF
63//