Index: classes/DelphesLongFormula.cc
===================================================================
--- classes/DelphesLongFormula.cc	(revision c74995760bbccf4bbea6fdeb2335cb5d20c62489)
+++ classes/DelphesLongFormula.cc	(revision c74995760bbccf4bbea6fdeb2335cb5d20c62489)
@@ -0,0 +1,127 @@
+/*
+ *  Delphes: a framework for fast simulation of a generic collider experiment
+ *  Copyright (C) 2012-2014  Universite catholique de Louvain (UCL), Belgium
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+
+#include "classes/DelphesLongFormula.h"
+
+#include "TString.h"
+
+#include <stdexcept>
+
+using namespace std;
+
+//------------------------------------------------------------------------------
+
+DelphesLongFormula::DelphesLongFormula() :
+  TFormula()
+{
+}
+
+//------------------------------------------------------------------------------
+
+DelphesLongFormula::DelphesLongFormula(const char *name, const char *expression) :
+  TFormula()
+{
+}
+
+//------------------------------------------------------------------------------
+
+DelphesLongFormula::~DelphesLongFormula()
+{
+}
+
+//------------------------------------------------------------------------------
+
+Int_t DelphesLongFormula::Compile(const char *expression)
+{
+  TString buffer;
+  const char *it;
+  for(it = expression; *it; ++it)
+  {
+    if(*it == ' ' || *it == '\t' || *it == '\r' || *it == '\n' || *it == '\\' ) continue;
+    buffer.Append(*it);
+  }
+
+  buffer.ReplaceAll("pt", "[pt]");
+  buffer.ReplaceAll("eta", "[eta]");
+  buffer.ReplaceAll("phi", "[phi]");
+  buffer.ReplaceAll("energy", "[energy]");
+  buffer.ReplaceAll("d0", "[d0]");
+  buffer.ReplaceAll("dz", "[dz]");
+  buffer.ReplaceAll("ctgTheta", "[ctgTheta]");
+
+  #if ROOT_VERSION_CODE < ROOT_VERSION(6,0,0)
+    TFormula::SetMaxima(100000,1000,1000000);
+  #endif
+  
+  if(TFormula::Compile(buffer) != 0)
+  {
+    throw runtime_error("Invalid Long Formula.");
+  }
+
+  return 0;
+}
+
+//------------------------------------------------------------------------------
+
+Double_t DelphesLongFormula::Eval(Double_t pt, 
+                                  Double_t eta, 
+                                  Double_t phi, 
+                                  Double_t energy,
+                                  Double_t d0,
+                                  Double_t dz,
+                                  Double_t ctgTheta
+                                 )
+{
+
+  TVarNameMap fVarNameMap;
+  TVarValMap fVarValMap;
+
+  fVarNameMap[this->GetParNumber("pt")]= "pt";
+  fVarNameMap[this->GetParNumber("eta")]= "eta";
+  fVarNameMap[this->GetParNumber("phi")]= "phi";
+  fVarNameMap[this->GetParNumber("energy")]= "energy";
+  fVarNameMap[this->GetParNumber("d0")]= "d0";
+  fVarNameMap[this->GetParNumber("dz")]= "dz";
+  fVarNameMap[this->GetParNumber("ctgTheta")]= "ctgTheta";
+
+  fVarValMap["pt"]= pt;      
+  fVarValMap["eta"]= eta;
+  fVarValMap["phi"]= phi;
+  fVarValMap["energy"]= energy;
+  fVarValMap["d0"]= d0;
+  fVarValMap["dz"]= dz;
+  fVarValMap["ctgTheta"]= ctgTheta;
+
+  Double_t vals[7];
+
+  Int_t j = 0;
+  for (Int_t i=0; i != 7; i++)
+  {
+     if ( fVarNameMap.find(i) != fVarNameMap.end() ) 
+     {
+        TString var_name = fVarNameMap[i];
+        vals[i] = fVarValMap[var_name];
+     }
+     else
+        vals[i] = 0.;
+  }   
+  return EvalPar(nullptr, vals);
+}
+
+//------------------------------------------------------------------------------
Index: classes/DelphesLongFormula.h
===================================================================
--- classes/DelphesLongFormula.h	(revision c74995760bbccf4bbea6fdeb2335cb5d20c62489)
+++ classes/DelphesLongFormula.h	(revision c74995760bbccf4bbea6fdeb2335cb5d20c62489)
@@ -0,0 +1,50 @@
+/*
+ *  Delphes: a framework for fast simulation of a generic collider experiment
+ *  Copyright (C) 2012-2014  Universite catholique de Louvain (UCL), Belgium
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef DelphesLongFormula_h
+#define DelphesLongFormula_h
+
+#include "TFormula.h"
+
+class DelphesLongFormula: public TFormula
+{
+public:
+
+  DelphesLongFormula();
+  DelphesLongFormula(const char *name, const char *expression);
+
+  ~DelphesLongFormula();
+
+  Int_t Compile(const char *expression);
+
+  Double_t Eval(Double_t pt, 
+                Double_t eta = 0, 
+                Double_t phi = 0, 
+                Double_t energy = 0,
+                Double_t d0 = 0,
+                Double_t dz = 0,
+                Double_t ctgTheta = 0
+                );
+
+  typedef std::map<Int_t,TString> TVarNameMap; //!
+  typedef std::map<TString, Double_t> TVarValMap; //!
+
+  
+};
+
+#endif /* DelphesLongFormula_h */
