#ifndef _utl_FunctionEvaluator_h_
#define _utl_FunctionEvaluator_h_

#include <string>
#include <CLHEP/Evaluator/Evaluator.h>


namespace utl {

  /**
    \class FunctionEvaluator FunctionEvaluator.h "utl/FunctionEvaluator.h"

    \brief Evaluate functions given in a string.

    \author Darko Veberic
    \date 27 Aug 2009
    \version $Id$
    \ingroup math
  */

  class FunctionEvaluator {
  public:
    FunctionEvaluator(const std::string& function,
                      const std::string& independentVariableName = "x");

    const std::string& GetFunction() const
    { return fFunction; }

    const std::string& GetIndependentVariableName() const
    { return fIndependentVariableName; }

    double operator()(const double x);

    void SetFunction(const std::string& function)
    { fFunction = function; }

    void SetIndependentVariableName(const std::string& name)
    { fIndependentVariableName = name; }

    private:
      std::string fFunction;
      std::string fIndependentVariableName;
      HepTool::Evaluator fEvaluator;
  };

}


#endif