#include "tmvaglob.C"

// this macro plots the correlation matrix of the various input
// variables used in TMVA (e.g. running TMVAnalysis.C).  Signal and
// Background are plotted separately

// input: - Input file (result from TMVA),
//        - use of colors or grey scale
//        - use of TMVA plotting TStyle
void correlations( TString fin = "TMVA.root", Bool_t greyScale = kFALSE, Bool_t useTMVAStyle = kTRUE )
{
   // set style and remove existing canvas'
   TMVAGlob::Initialize( useTMVAStyle );

   // checks if file with name "fin" is already open, and if not opens one
   TFile* file = TMVAGlob::OpenFile( fin );  

   // signal and background
   const TString hName[2] = { "CorrelationMatrixS", "CorrelationMatrixB" };
   const Int_t width = 600;
   for (Int_t ic=0; ic<2; ic++) {

      TCanvas* c = new TCanvas( hName[ic], 
                                Form("Correlations between MVA input variables (%s)", (ic==0?"signal":"background")), 
                                ic*(width+5)+200, 0, width, width ); 
      Float_t newMargin1 = 0.13;
      Float_t newMargin2 = 0.15;
      if (TMVAGlob::UsePaperStyle) newMargin2 = 0.13;

      c->SetGrid();
      c->SetTicks();
      c->SetLeftMargin  ( newMargin2 );
      c->SetBottomMargin( newMargin2 );
      c->SetRightMargin ( newMargin1 );
      c->SetTopMargin   ( newMargin1 );
      gStyle->SetPalette( 1, 0 );

      TH2* h2 = file->Get( hName[ic] );

      gStyle->SetPaintTextFormat( "3g" );

      h2->SetMarkerSize( 1.5 );
      h2->SetMarkerColor( 0 );
      Float_t labelSize = 0.040;
      h2->GetXaxis()->SetLabelSize( labelSize );
      h2->GetYaxis()->SetLabelSize( labelSize );
      h2->LabelsOption( "d" );
      h2->SetLabelOffset( 0.011 );// label offset on x axis    

      h2->Draw("colz"); // color pads   
      c->Update();

      // modify properties of paletteAxis
      TPaletteAxis* paletteAxis = (TPaletteAxis*)h2->GetListOfFunctions()->FindObject( "palette" );
      paletteAxis->SetLabelSize( 0.03 );
      paletteAxis->SetX1NDC( paletteAxis->GetX1NDC() + 0.02 );

      h2->Draw("textsame");  // add text

      // add comment    
      TText* t = new TText( 0.53, 0.88, "Linear correlation coefficients in %" );
      t->SetNDC();
      t->SetTextSize( 0.026 );
      t->AppendPad();    

      // TMVAGlob::plot_logo( );
      c->Update();

      TString fname = "plots/";
      fname += hName[ic];
      TMVAGlob::imgconv( c, fname );
   }
}