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Example.C

Example of using this class

void
Example(Bool_t fit=true)
{
// Load the class - if not already done
if (!gROOT->GetClass("GraphSysErr"))
gROOT->LoadMacro("GraphSysErr.C+g");
// Adjust size along X of common errors
gStyle->SetErrorX(.2);
// Adjust size of hat, cap, ... - depends on canvas size!
gStyle->SetEndErrorSize(10);
// Make our object
GraphSysErr* gse = new GraphSysErr("foo", "Gaussian");
// Draw data with-out ticks
gse->SetXTitle("X");
gse->SetYTitle("Y");
// Set some key/value pairs
gse->SetKey("laboratory", "The Center");
gse->SetKey("accelerator", "Mega Collider");
gse->SetKey("detector", "Huge Experiment");
gse->SetKey("author", "Christensen");
gse->SetKey("reference","Jour.All.Things A1,999");
gse->SetKey("doi","9999-9999-9999-9999");
gse->SetKey("abstract", "The data");
gse->SetKey("location", "In the paper");
gse->SetKey("reackey", "graviton -> tachyons");
gse->SetKey("obskey", "GUT");
// Adding qualifiers
gse->AddQualifier("question", "Life, universe, and everything");
// Two sources of common errors one relative, one absolue
UInt_t cm1 = gse->DefineCommon("Common 0.05", false, .05);
UInt_t cm2 = gse->DefineCommon("Common 10%", true, .1);
// Two sources of point-to-point errors, one relative, one absolute
UInt_t pp1 = gse->DeclarePoint2Point("Point-to-Point 0.1-0.2", true);
UInt_t pp2 = gse->DeclarePoint2Point("Point-to-Point 5-10%", false);
// Set options on summed errors (in case of option COMBINED)
gse->SetSumLineColor(kRed+2);
gse->SetSumLineWidth(2);
gse->SetSumTitle("All errors");
// Set attributes of common errors
gse->SetSysFillColor(cm1, kRed+2);
gse->SetSysFillStyle(cm1, 3001);
gse->SetSysLineColor(cm1, kRed+2);
gse->SetSysFillColor(cm2, kCyan+2);
gse->SetSysFillStyle(cm2, 3001);
// Set attributes of other errors
gse->SetSysLineColor(pp1, kBlue+2);
gse->SetSysLineWidth(pp1, 2);
gse->SetSysLineColor(pp2, kGreen+2);
gse->SetSysLineWidth(pp2, 3);
// Fill a histogram with a Guassian random deviate
TH1* h = new TH1F("h", "h", 30, -3, 3);
h->Sumw2();
h->SetDirectory(0);
h->FillRandom("gaus",1000);
h->Scale(1./1000, "width");
// Fill in the data points
for (Int_t i = 0; i < h->GetNbinsX(); i++) {
Int_t bin = i+1;
Double_t x = h->GetXaxis()->GetBinCenter(bin);
Double_t y = h->GetBinContent(bin);
Double_t sta = h->GetBinError(bin);
Double_t w = h->GetXaxis()->GetBinWidth(bin);
// Set data
gse->SetPoint(i, x, y);
gse->SetPointError(i, w/2, w/2);
gse->SetStatError(i, sta);
// Set point-to-point errors
gse->SetSysError(pp1, i, 0., gRandom->Uniform(0.1, 0.2));
gse->SetSysError(pp2, i, 0., 0.,
gRandom->Uniform(0.05, 0.1),
gRandom->Uniform(0.05, 0.1));
}
// Remove temporary histogram
delete h;
// Build our canvas
TCanvas* c = new TCanvas("c","c", 1400, 1000);
c->SetFillColor(0);
c->SetFillStyle(0);
c->SetTopMargin(0.01);
c->SetRightMargin(0.01);
// Draw or fit (and draw) a Guassian to the data
const char* option = "STACK stat axis quad split max west";
if (!fit)
gse->Draw(option);
else
gse->Fit("gaus", "SQ", option, -3, 3);
// Make a legend
TLegend* l = c->BuildLegend(0.7,0.7,0.97,0.97);
l->SetFillColor(0);
l->SetFillStyle(0);
l->SetBorderSize(0);
// update the canvas and print
c->Modified();
c->Update();
c->cd();
c->Print("Example.png");
}