void BuildAPdf() {
// Build the pdf
AxisCollection ax;
ax.AddAxis(PdfAxis("energy", 0, 3, 100));
ax.AddAxis(PdfAxis("radius", 0, 1, 100));
ax.AddAxis(PdfAxis("psd", 0, 1, 100));
ax.AddAxis(PdfAxis("psd2", 0, 1, 100));
BinnedPdf pdf(ax);
std::vector<size_t> indicies;
indicies.push_back(0);
indicies.push_back(1);
indicies.push_back(2);
indicies.push_back(3);
pdf.SetDataRep(DataRepresentation(indicies));
// Get the data
ROOTHandle rHandle(fileName, treeName);
unsigned nEntries = rHandle.GetNEntries();
std::cout << nEntries << " Entries to fill" << std::endl;
// Fill the Pdf
for(size_t i = 0; i < nEntries; i++) {
pdf.Fill(rHandle.GetEntry(i));
}
return;
}
int main(){
////////////////////
// 1. Set Up PDFs //
////////////////////
// Set up binning
AxisCollection axes;
axes.AddAxis(PdfAxis("energy", 2, 3, 10, "Energy"));
// Only interested in first bit of data ntuple
DataRepresentation dataRep(0);
// Set up pdf with these bins in this observable
BinnedPdf bgPdf(axes); bgPdf.SetDataRep(dataRep);
BinnedPdf signalPdf(axes); signalPdf.SetDataRep(dataRep);
std::cout << "Initialised Pdfs" << std::endl;
/////////////////////////////////////
// 2. Fill with data and normalise //
/////////////////////////////////////
ROOTNtuple bgMC("filename.root", "treename");
ROOTNtuple signalMC("filename.root", "treename");
for(size_t i = 0; i < 10; i++){
bgPdf.Fill(bgMC.GetEntry(i));
}
for(size_t i = 0; i < 10; i++){
signalPdf.Fill(signalMC.GetEntry(i));
}
bgPdf.Normalise();
signalPdf.Normalise();
std::cout << "Filled pdfs " << std::endl;
////////////////////////////
// 3. Set Up LH function //
////////////////////////////
BinnedNLLH lhFunction;
lhFunction.SetDataSet(&signalMC); // initialise withe the data set
lhFunction.AddPdf(bgPdf);
lhFunction.AddPdf(signalPdf);
std::cout << "Built LH function " << std::endl;
// Set up the optimisation
GridSearch gSearch(&lhFunction);
std::vector<double> minima(2, 0);
std::vector<double> maxima(2, 100);
std::vector<double> stepsizes(2, 1);
gSearch.SetMaxima(maxima);
gSearch.SetMinima(minima);
gSearch.SetStepSizes(stepsizes);
////////////
// 4. Fit //
////////////
gSearch.Optimise();
std::vector<double> fit = gSearch.GetFitResult().GetBestFit();
std::cout << "Best Fit: " << std::endl;
for(size_t i = 0; i < fit.size(); i++)
std::cout << fit.at(i) << "\t";
std::cout << std::endl;
return 0;
}
BinnedED
BinnedEDShrinker::ShrinkDist(const BinnedED& dist_) const{
// No buffer no problem. FIXME: what about if all the values are zero?
if (!fBuffers.size())
return dist_;
size_t nDims = dist_.GetNDims();
// FIXME Add a check to see if the non zero entries of fBuffers are in the pdf and give warning
// 1. Build new axes. ShrinkPdf method just makes a copy if buffer size is zero
AxisCollection newAxes;
const std::vector<size_t> distDataIndices = dist_.GetObservables().GetIndices();
size_t dataIndex = 0;
for(size_t i = 0; i < nDims; i++){
dataIndex = distDataIndices.at(i);
if (!fBuffers.count(dataIndex))
newAxes.AddAxis(dist_.GetAxes().GetAxis(i));
else
newAxes.AddAxis(ShrinkAxis(dist_.GetAxes().GetAxis(i),
fBuffers.at(dataIndex).first,
fBuffers.at(dataIndex).second));
}
// 2. Initialise the new pdf with same data rep
BinnedED newDist(dist_.GetName() + "_shrunk", newAxes);
newDist.SetObservables(dist_.GetObservables());
// 3. Fill the axes
std::vector<size_t> newIndices(dist_.GetNDims()); // same as old, just corrected for overflow
int offsetIndex = 0; // note taking difference of two unsigneds
size_t newBin = 0; // will loop over dims and use this to assign bin # corrected for overflow
const AxisCollection& axes = dist_.GetAxes();
double content = 0;
// bin by bin of old pdf
for(size_t i = 0; i < dist_.GetNBins(); i++){
content = dist_.GetBinContent(i);
if(!content) // no content no problem
continue;
// work out the index of this bin in the new shrunk pdf.
for(size_t j = 0; j < nDims; j++){
offsetIndex = axes.UnflattenIndex(i, j); // the index in old pdf
if (fBuffers.count(distDataIndices.at(j))) // offset by lower buffer if nonzero
offsetIndex -= fBuffers.at(distDataIndices.at(j)).first;
// Correct the ones that fall in the buffer regions
// bins in the lower buffer have negative index. Put in first bin in fit region or ignore
if (offsetIndex < 0){
offsetIndex = 0;
if(!fUsingOverflows)
content = 0;
}
// bins in the upper buffer have i > number of bins in axis j. Do the same
if (offsetIndex >= newAxes.GetAxis(j).GetNBins()){
offsetIndex = newAxes.GetAxis(j).GetNBins() - 1;
if (!fUsingOverflows)
content = 0;
}
newIndices[j] = offsetIndex;
}
// Fill
newBin = newAxes.FlattenIndices(newIndices);
newDist.AddBinContent(newBin, content);
}
return newDist;
}