StandardHistFactoryPlotsWithCategories.C:

/*
StandardHistFactoryPlotsWithCategories

Author: Kyle Cranmer
date: Spring. 2011

This is a standard demo that can be used with any ROOT file 
prepared in the standard way.  You specify:
 - name for input ROOT file
 - name of workspace inside ROOT file that holds model and data
 - name of ModelConfig that specifies details for calculator tools
 - name of dataset 

With default parameters the macro will attempt to run the 
standard hist2workspace example and read the ROOT file
that it produces.

The macro will scan through all the categories in a simPdf find the corresponding
observable.  For each cateogry, it will loop through each of the nuisance parameters
and plot 
   - the data 
   - the nominal model (blue) 
   - the +Nsigma (red)
   - the -Nsigma (green)

You can specify how many sigma to vary by changing nSigmaToVary.
You can also change the signal rate by changing muVal.

The script produces a lot plots, you can merge them by doing:
gs -q -dNOPAUSE -dBATCH -sDEVICE=pdfwrite -sOutputFile=merged.pdf `ls *pdf`
*/

#include "TFile.h"
#include "TROOT.h"
#include "TCanvas.h"
#include "TList.h"
#include "TMath.h"
#include "RooWorkspace.h"
#include "RooAbsData.h"

#include "RooStats/ModelConfig.h"
#include "RooStats/ProfileInspector.h"

using namespace RooFit;
using namespace RooStats;

void StandardHistFactoryPlotsWithCategories(const char* infile = "",
		      const char* workspaceName = "combined",
		      const char* modelConfigName = "ModelConfig",
		      const char* dataName = "obsData"){


  double nSigmaToVary=5.;
  double muVal=0;
  bool doFit=false;

  /////////////////////////////////////////////////////////////
  // First part is just to access a user-defined file 
  // or create the standard example file if it doesn't exist
  ////////////////////////////////////////////////////////////
  const char* filename = "";
  if (!strcmp(infile,""))
    filename = "results/example_combined_GammaExample_model.root";
  else
    filename = infile;
  // Check if example input file exists
  TFile *file = TFile::Open(filename);

  // if input file was specified byt not found, quit
  if(!file && strcmp(infile,"")){
    cout <<"file not found" << endl;
    return;
  } 

  // if default file not found, try to create it
  if(!file ){
    // Normally this would be run on the command line
    cout <<"will run standard hist2workspace example"<<endl;
    gROOT->ProcessLine(".! prepareHistFactory .");
    gROOT->ProcessLine(".! hist2workspace config/example.xml");
    cout <<"\n\n---------------------"<<endl;
    cout <<"Done creating example input"<<endl;
    cout <<"---------------------\n\n"<<endl;
  }

  // now try to access the file again
  file = TFile::Open(filename);
  if(!file){
    // if it is still not there, then we can't continue
    cout << "Not able to run hist2workspace to create example input" <<endl;
    return;
  }

  
  /////////////////////////////////////////////////////////////
  // Tutorial starts here
  ////////////////////////////////////////////////////////////

  // get the workspace out of the file
  RooWorkspace* w = (RooWorkspace*) file->Get(workspaceName);
  if(!w){
    cout <<"workspace not found" << endl;
    return;
  }

  // get the modelConfig out of the file
  ModelConfig* mc = (ModelConfig*) w->obj(modelConfigName);

  // get the modelConfig out of the file
  RooAbsData* data = w->data(dataName);

  // make sure ingredients are found
  if(!data || !mc){
    w->Print();
    cout << "data or ModelConfig was not found" <<endl;
    return;
  }

  //////////////////////////////////////////////
  // now use the profile inspector

  RooRealVar* obs = (RooRealVar*)mc->GetObservables()->first();
  TList* list = new TList();

 
  RooRealVar * firstPOI = dynamic_cast<RooRealVar*>(mc->GetParametersOfInterest()->first());

  firstPOI->setVal(muVal);
  //  firstPOI->setConstant();
  if(doFit){
    mc->GetPdf()->fitTo(*data);
  }

  ////////////////////////////////////////
  ////////////////////////////////////////
  ////////////////////////////////////////

  mc->GetNuisanceParameters()->Print("v");
  int  nPlotsMax = 1000;
  cout <<" check expectedData by category"<<endl;
  RooDataSet* simData=NULL;
  RooSimultaneous* simPdf = NULL;
  if(strcmp(mc->GetPdf()->ClassName(),"RooSimultaneous")==0){
    cout <<"Is a simultaneous PDF"<<endl;
    simPdf = (RooSimultaneous)(mc->GetPdf());
  } else {
    cout <<"Is not a simultaneous PDF"<<endl;
  }



  if(doFit) {
    RooCategory* channelCat = (RooCategory*) (&simPdf->indexCat());
    TIterator* iter = channelCat->typeIterator() ;
    RooCatType* tt = NULL;
    tt=(RooCatType*) iter->Next();  
    RooAbsPdf* pdftmp = ((RooSimultaneous*)mc->GetPdf())->getPdf(tt->GetName()) ;
    RooArgSet* obstmp = pdftmp->getObservables(*mc->GetObservables()) ;
    obs = ((RooRealVar*)obstmp->first());
    RooPlot* frame = obs->frame();
    cout <<Form("%s==%s::%s",channelCat->GetName(),channelCat->GetName(),tt->GetName())<<endl;
    cout << tt->GetName() << " " << channelCat->getLabel() <<endl;
    data->plotOn(frame,MarkerSize(1),Cut(Form("%s==%s::%s",channelCat->GetName(),channelCat->GetName(),tt->GetName())),DataError(RooAbsData::None));
    
    Double_t normCount = data->sumEntries(Form("%s==%s::%s",channelCat->GetName(),channelCat->GetName(),tt->GetName())) ;
    
    pdftmp->plotOn(frame,LineWidth(2.),Normalization(normCount,RooAbsReal::NumEvent)) ;
    frame->Draw();
    cout <<"expected events = " << mc->GetPdf()->expectedEvents(*data->get()) <<endl;
    return;
  }



  int nPlots=0;
  if(!simPdf){

    TIterator* it = mc->GetNuisanceParameters()->createIterator();
    RooRealVar* var = NULL;
    while(var = (RooRealVar*) it->Next()){
      RooPlot* frame = obs->frame();
      frame->SetYTitle(var->GetName());
      data->plotOn(frame,MarkerSize(1));
      var->setVal(0);
      mc->GetPdf()->plotOn(frame,LineWidth(1.));
      var->setVal(1);
      mc->GetPdf()->plotOn(frame,LineColor(kRed),LineStyle(kDashed),LineWidth(1));
      var->setVal(-1);
      mc->GetPdf()->plotOn(frame,LineColor(kGreen),LineStyle(kDashed),LineWidth(1));
      list->Add(frame);
      var->setVal(0);
    }
    
  
  } else {
    RooCategory* channelCat = (RooCategory*) (&simPdf->indexCat());
    //    TIterator* iter = simPdf->indexCat().typeIterator() ;
    TIterator* iter = channelCat->typeIterator() ;
    RooCatType* tt = NULL;
    while(nPlots<nPlotsMax && (tt=(RooCatType*) iter->Next())) {

      cout << "on type " << tt->GetName() << " " << endl;
      // Get pdf associated with state from simpdf
      RooAbsPdf* pdftmp = simPdf->getPdf(tt->GetName()) ;
	
      // Generate observables defined by the pdf associated with this state
      RooArgSet* obstmp = pdftmp->getObservables(*mc->GetObservables()) ;
      //      obstmp->Print();


      obs = ((RooRealVar*)obstmp->first());

      TIterator* it = mc->GetNuisanceParameters()->createIterator();
      RooRealVar* var = NULL;
      while(nPlots<nPlotsMax && (var = (RooRealVar*) it->Next())){
	TCanvas* c2 = new TCanvas("c2");
	RooPlot* frame = obs->frame();
	frame->SetName(Form("frame%d",nPlots));
	frame->SetYTitle(var->GetName());

	cout <<Form("%s==%s::%s",channelCat->GetName(),channelCat->GetName(),tt->GetName())<<endl;
	cout << tt->GetName() << " " << channelCat->getLabel() <<endl;
	data->plotOn(frame,MarkerSize(1),Cut(Form("%s==%s::%s",channelCat->GetName(),channelCat->GetName(),tt->GetName())),DataError(RooAbsData::None));

	Double_t normCount = data->sumEntries(Form("%s==%s::%s",channelCat->GetName(),channelCat->GetName(),tt->GetName())) ;
	  
	if(strcmp(var->GetName(),"Lumi")==0){
	  cout <<"working on lumi"<<endl;
	  var->setVal(combined->var("nominalLumi")->getVal());
	  var->Print();
	} else{
	  var->setVal(0);
	}
	//	w->allVars().Print("v");
	//	mc->GetNuisanceParameters()->Print("v");
	//	pdftmp->plotOn(frame,LineWidth(2.));
	//	mc->GetPdf()->plotOn(frame,LineWidth(2.),Slice(*channelCat,tt->GetName()),ProjWData(*data));
	//pdftmp->plotOn(frame,LineWidth(2.),Slice(*channelCat,tt->GetName()),ProjWData(*data));
	normCount = pdftmp->expectedEvents(*obs);
	pdftmp->plotOn(frame,LineWidth(2.),Normalization(normCount,RooAbsReal::NumEvent)) ;

	if(strcmp(var->GetName(),"Lumi")==0){
	  cout <<"working on lumi"<<endl;
	  var->setVal(combined->var("nominalLumi")->getVal()+0.05);
	  var->Print();
	} else{
	  var->setVal(nSigmaToVary);
	}
	//	pdftmp->plotOn(frame,LineColor(kRed),LineStyle(kDashed),LineWidth(2));
	//	mc->GetPdf()->plotOn(frame,LineColor(kRed),LineStyle(kDashed),LineWidth(2.),Slice(*channelCat,tt->GetName()),ProjWData(*data));
	//pdftmp->plotOn(frame,LineColor(kRed),LineStyle(kDashed),LineWidth(2.),Slice(*channelCat,tt->GetName()),ProjWData(*data));
	normCount = pdftmp->expectedEvents(*obs);
	pdftmp->plotOn(frame,LineWidth(2.),LineColor(kRed),LineStyle(kDashed),Normalization(normCount,RooAbsReal::NumEvent)) ;

	if(strcmp(var->GetName(),"Lumi")==0){
	  cout <<"working on lumi"<<endl;
	  var->setVal(combined->var("nominalLumi")->getVal()-0.05);
	  var->Print();
	} else{
	  var->setVal(-nSigmaToVary);
	}
	//	pdftmp->plotOn(frame,LineColor(kGreen),LineStyle(kDashed),LineWidth(2));
	//	mc->GetPdf()->plotOn(frame,LineColor(kGreen),LineStyle(kDashed),LineWidth(2),Slice(*channelCat,tt->GetName()),ProjWData(*data));
	//pdftmp->plotOn(frame,LineColor(kGreen),LineStyle(kDashed),LineWidth(2),Slice(*channelCat,tt->GetName()),ProjWData(*data));
	normCount = pdftmp->expectedEvents(*obs);
	pdftmp->plotOn(frame,LineWidth(2.),LineColor(kGreen),LineStyle(kDashed),Normalization(normCount,RooAbsReal::NumEvent)) ;



	// set them back to normal
	if(strcmp(var->GetName(),"Lumi")==0){
	  cout <<"working on lumi"<<endl;
	  var->setVal(combined->var("nominalLumi")->getVal());
	  var->Print();
	} else{
	  var->setVal(0);
	}

	list->Add(frame);

	// quit making plots
	++nPlots;

	frame->Draw();
	c2->SaveAs(Form("%s_%s_%s.pdf",tt->GetName(),obs->GetName(),var->GetName()));
	delete c2;
      }
    }
  }



  ////////////////////////////////////////
  ////////////////////////////////////////
  ////////////////////////////////////////

    // now make plots
    TCanvas* c1 = new TCanvas("c1","ProfileInspectorDemo",800,200);
    if(list->GetSize()>4){
      double n = list->GetSize();
      int nx = (int)sqrt(n) ;
      int ny = TMath::CeilNint(n/nx);
      nx = TMath::CeilNint( sqrt(n) );
      c1->Divide(ny,nx);
    } else
      c1->Divide(list->GetSize());
    for(int i=0; i<list->GetSize(); ++i){
      c1->cd(i+1);
      list->At(i)->Draw();
    }
 



  
}