include/root/RooBrentRootFinder.h

0001 /*****************************************************************************
0002  * Project: RooFit                                                           *
0003  * Package: RooFitCore                                                       *
0004  *    File: $Id: RooBrentRootFinder.h,v 1.6 2007/05/11 09:11:30 verkerke Exp $
0005  * Authors:                                                                  *
0006  *   WV, Wouter Verkerke, UC Santa Barbara, verkerke@slac.stanford.edu       *
0007  *   DK, David Kirkby,    UC Irvine,         dkirkby@uci.edu                 *
0008  *                                                                           *
0009  * Copyright (c) 2000-2005, Regents of the University of California          *
0010  *                          and Stanford University. All rights reserved.    *
0011  *                                                                           *
0012  * Redistribution and use in source and binary forms,                        *
0013  * with or without modification, are permitted according to the terms        *
0014  * listed in LICENSE (http://roofit.sourceforge.net/license.txt)             *
0015  *****************************************************************************/
0016 #ifndef ROO_BRENT_ROOT_FINDER
0017 #define ROO_BRENT_ROOT_FINDER
0018
0019 #include <Rtypes.h>
0020
0021 class RooAbsFunc;
0022
0023 class RooBrentRootFinder {
0024 public:
0025   RooBrentRootFinder(const RooAbsFunc& function);
0026   virtual ~RooBrentRootFinder() = default;
0027
0028   bool findRoot(double &result, double xlo, double xhi, double value= 0) const;
0029
0030   /// Set convergence tolerance parameter
0031   void setTol(double tol) {
0032     _tol = tol ;
0033   }
0034
0035 protected:
0036   static constexpr int MaxIterations = 512;
0037
0038   const RooAbsFunc *_function; ///< Pointer to input function
0039   bool _valid;               ///< True if current state is valid
0040
0041   double _tol ;
0042
0043   ClassDef(RooBrentRootFinder,0)
0044 };
0045
0046 #endif