1 // Created on: 1991-03-14 2 // Created by: Laurent PAINNOT 3 // Copyright (c) 1991-1999 Matra Datavision 4 // Copyright (c) 1999-2014 OPEN CASCADE SAS 5 // 6 // This file is part of Open CASCADE Technology software library. 7 // 8 // This library is free software; you can redistribute it and/or modify it under 9 // the terms of the GNU Lesser General Public License version 2.1 as published 10 // by the Free Software Foundation, with special exception defined in the file 11 // OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT 12 // distribution for complete text of the license and disclaimer of any warranty. 13 // 14 // Alternatively, this file may be used under the terms of Open CASCADE 15 // commercial license or contractual agreement. 16 17 #ifndef _math_BissecNewton_HeaderFile 18 #define _math_BissecNewton_HeaderFile 19 20 #include <Standard.hxx> 21 #include <Standard_DefineAlloc.hxx> 22 #include <Standard_Handle.hxx> 23 24 #include <Standard_Boolean.hxx> 25 #include <math_Status.hxx> 26 #include <Standard_Real.hxx> 27 #include <Standard_Integer.hxx> 28 #include <Standard_OStream.hxx> 29 class StdFail_NotDone; 30 class math_FunctionWithDerivative; 31 32 33 34 //! This class implements a combination of Newton-Raphson and bissection 35 //! methods to find the root of the function between two bounds. 36 //! Knowledge of the derivative is required. 37 class math_BissecNewton 38 { 39 public: 40 41 DEFINE_STANDARD_ALLOC 42 43 44 //! Constructor. 45 //! @param theXTolerance - algorithm tolerance. 46 Standard_EXPORT math_BissecNewton(const Standard_Real theXTolerance); 47 48 49 //! A combination of Newton-Raphson and bissection methods is done to find 50 //! the root of the function F between the bounds Bound1 and Bound2 51 //! on the function F. 52 //! The tolerance required on the root is given by TolX. 53 //! The solution is found when: 54 //! abs(Xi - Xi-1) <= TolX and F(Xi) * F(Xi-1) <= 0 55 //! The maximum number of iterations allowed is given by NbIterations. 56 Standard_EXPORT void Perform (math_FunctionWithDerivative& F, const Standard_Real Bound1, const Standard_Real Bound2, const Standard_Integer NbIterations = 100); 57 58 59 //! This method is called at the end of each iteration to check if the 60 //! solution has been found. 61 //! It can be redefined in a sub-class to implement a specific test to 62 //! stop the iterations. 63 virtual Standard_Boolean IsSolutionReached (math_FunctionWithDerivative& theFunction); 64 65 //! Tests is the root has been successfully found. 66 Standard_Boolean IsDone() const; 67 68 //! returns the value of the root. 69 //! Exception NotDone is raised if the minimum was not found. 70 Standard_Real Root() const; 71 72 //! returns the value of the derivative at the root. 73 //! Exception NotDone is raised if the minimum was not found. 74 Standard_Real Derivative() const; 75 76 //! returns the value of the function at the root. 77 //! Exception NotDone is raised if the minimum was not found. 78 Standard_Real Value() const; 79 80 //! Prints on the stream o information on the current state 81 //! of the object. 82 //! Is used to redifine the operator <<. 83 Standard_EXPORT void Dump (Standard_OStream& o) const; 84 85 //! Destructor 86 Standard_EXPORT virtual ~math_BissecNewton(); 87 88 89 90 91 protected: 92 93 94 95 math_Status TheStatus; 96 Standard_Real XTol; 97 Standard_Real x; 98 Standard_Real dx; 99 Standard_Real f; 100 Standard_Real df; 101 102 103 private: 104 105 106 107 Standard_Boolean Done; 108 109 110 }; 111 112 113 #include <math_BissecNewton.lxx> 114 115 116 117 118 119 #endif // _math_BissecNewton_HeaderFile 120