minor change to macro

diff --git a/TOF/ReadT0FillReference.C b/TOF/ReadT0FillReference.C
index 6561b92c618cbddc87164bdc634d5b9f6d882a90..b43bc9f09c2433a4ca42750c97f589b2c9c0db45 100644 (file)
--- a/TOF/ReadT0FillReference.C
+++ b/TOF/ReadT0FillReference.C
@@ -6,8 +6,46 @@ ReadT0FillReference(Int_t run, Int_t year = 2010)
   cdb->SetDefaultStorage(Form("alien://folder=/alice/data/%d/Reference", year));
   cdb->SetRun(run);
   AliCDBEntry *cdbe = cdb->Get("TOF/Calib/T0Fill");
-  TH1F *h = (TH1F *)cdbe->GetObject();
-  h->DrawCopy();
-  return h;
+  TH1F *hT0Fill = (TH1F *)cdbe->GetObject();
+
+  /* rebin until maximum bin has required minimum entries */
+  Int_t maxBin = hT0Fill->GetMaximumBin();
+  Float_t maxBinContent = hT0Fill->GetBinContent(maxBin);
+  Float_t binWidth = hT0Fill->GetBinWidth(maxBin);
+  while (maxBinContent < 400 && binWidth < 90.) {
+    hT0Fill->Rebin(2);
+    maxBin = hT0Fill->GetMaximumBin();
+    maxBinContent = hT0Fill->GetBinContent(maxBin);
+    binWidth = hT0Fill->GetBinWidth(maxBin);
+  }
+  Float_t maxBinCenter = hT0Fill->GetBinCenter(maxBin);
+
+  /* rough fit of the edge */
+  TF1 *gaus = (TF1 *)gROOT->GetFunction("landau");
+  gaus->SetParameter(1, maxBinCenter);
+  Float_t fitMin = maxBinCenter - 1000.; /* fit from 1 ns before max */
+  Float_t fitMax = maxBinCenter + 1000.; /* fit until 1 ns above max */
+  hT0Fill->Fit("gaus", "q0", "", fitMin, fitMax);
+  /* better fit of the edge */
+  Float_t mean, sigma;
+  for (Int_t istep = 0; istep < 10; istep++) {
+    mean = gaus->GetParameter(1);
+    sigma = gaus->GetParameter(2);
+    fitMin = mean - 2. * sigma;
+    fitMax = mean + 1. * sigma;
+    hT0Fill->Fit("landau", "q", "", fitMin, fitMax);
+  }
+  /* print params */
+  mean = gaus->GetParameter(1);
+  sigma = gaus->GetParameter(2);
+  Float_t meane = gaus->GetParError(1);
+  Float_t sigmae = gaus->GetParError(2);
+  printf("edge fit: mean  = %f +- %f ps\n", mean, meane);
+  printf("edge fit: sigma = %f +- %f ps\n", sigma, sigmae);
+
+  hT0Fill->DrawCopy();
+  gaus->Draw("same");
+
+  return hT0Fill;
 
 }