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Warning, file /include/opencascade/math_NewtonFunctionSetRoot.hxx was not indexed or was modified since last indexation (in which case cross-reference links may be missing, inaccurate or erroneous).

0001 // Created on: 1991-05-14
0002 // Created by: Laurent PAINNOT
0003 // Copyright (c) 1991-1999 Matra Datavision
0004 // Copyright (c) 1999-2014 OPEN CASCADE SAS
0005 //
0006 // This file is part of Open CASCADE Technology software library.
0007 //
0008 // This library is free software; you can redistribute it and/or modify it under
0009 // the terms of the GNU Lesser General Public License version 2.1 as published
0010 // by the Free Software Foundation, with special exception defined in the file
0011 // OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT
0012 // distribution for complete text of the license and disclaimer of any warranty.
0013 //
0014 // Alternatively, this file may be used under the terms of Open CASCADE
0015 // commercial license or contractual agreement.
0016 
0017 #ifndef _math_NewtonFunctionSetRoot_HeaderFile
0018 #define _math_NewtonFunctionSetRoot_HeaderFile
0019 
0020 #include <Standard.hxx>
0021 #include <Standard_DefineAlloc.hxx>
0022 
0023 #include <Standard_Integer.hxx>
0024 #include <math_Vector.hxx>
0025 #include <math_IntegerVector.hxx>
0026 #include <math_Matrix.hxx>
0027 #include <Standard_OStream.hxx>
0028 class math_FunctionSetWithDerivatives;
0029 
0030 //! This class computes the root of a set of N functions of N variables,
0031 //! knowing an initial guess at the solution and using the
0032 //! Newton Raphson algorithm. Knowledge of all the partial
0033 //! derivatives (Jacobian) is required.
0034 class math_NewtonFunctionSetRoot
0035 {
0036 public:
0037   DEFINE_STANDARD_ALLOC
0038 
0039   //! Initialize correctly all the fields of this class.
0040   //! The range (1, F.NbVariables()) must be especially respected for
0041   //! all vectors and matrix declarations.
0042   Standard_EXPORT math_NewtonFunctionSetRoot(math_FunctionSetWithDerivatives& theFunction,
0043                                              const math_Vector&               theXTolerance,
0044                                              const double                     theFTolerance,
0045                                              const int theNbIterations = 100);
0046 
0047   //! This constructor should be used in a sub-class to initialize
0048   //! correctly all the fields of this class.
0049   //! The range (1, F.NbVariables()) must be especially respected for
0050   //! all vectors and matrix declarations.
0051   //! The method SetTolerance must be called before performing the algorithm.
0052   Standard_EXPORT math_NewtonFunctionSetRoot(math_FunctionSetWithDerivatives& theFunction,
0053                                              const double                     theFTolerance,
0054                                              const int theNbIterations = 100);
0055 
0056   //! Destructor
0057   Standard_EXPORT virtual ~math_NewtonFunctionSetRoot();
0058 
0059   //! Initializes the tolerance values for the unknowns.
0060   Standard_EXPORT void SetTolerance(const math_Vector& XTol);
0061 
0062   //! The Newton method is done to improve the root of the function
0063   //! from the initial guess point. The solution is found when:
0064   //! abs(Xj - Xj-1)(i) <= XTol(i) and abs(Fi) <= FTol for all i;
0065   Standard_EXPORT void Perform(math_FunctionSetWithDerivatives& theFunction,
0066                                const math_Vector&               theStartingPoint);
0067 
0068   //! The Newton method is done to improve the root of the function
0069   //! from the initial guess point. Bounds may be given, to constrain the solution.
0070   //! The solution is found when:
0071   //! abs(Xj - Xj-1)(i) <= XTol(i) and abs(Fi) <= FTol for all i;
0072   Standard_EXPORT void Perform(math_FunctionSetWithDerivatives& theFunction,
0073                                const math_Vector&               theStartingPoint,
0074                                const math_Vector&               theInfBound,
0075                                const math_Vector&               theSupBound);
0076 
0077   //! This method is called at the end of each iteration to check if the
0078   //! solution is found.
0079   //! Vectors DeltaX, Fvalues and Jacobian Matrix are consistent with the
0080   //! possible solution Vector Sol and can be inspected to decide whether
0081   //! the solution is reached or not.
0082   virtual bool IsSolutionReached(math_FunctionSetWithDerivatives& F);
0083 
0084   //! Returns true if the computations are successful, otherwise returns false.
0085   bool IsDone() const;
0086 
0087   //! Returns the value of the root of function F.
0088   //! Exceptions
0089   //! StdFail_NotDone if the algorithm fails (and IsDone returns false).
0090   const math_Vector& Root() const;
0091 
0092   //! outputs the root vector in Root.
0093   //! Exception NotDone is raised if the root was not found.
0094   //! Exception DimensionError is raised if the range of Root is
0095   //! not equal to the range of the StartingPoint.
0096   void Root(math_Vector& Root) const;
0097 
0098   //! Outputs the state number associated with the solution
0099   //! vector root.
0100   int StateNumber() const;
0101 
0102   //! Returns the matrix value of the derivative at the root.
0103   //! Exception NotDone is raised if the root was not found.
0104   const math_Matrix& Derivative() const;
0105 
0106   //! Outputs the matrix value of the derivative at the root in
0107   //! Der.
0108   //! Exception NotDone is raised if the root was not found.
0109   //! Exception DimensionError is raised if the range of Der is
0110   //! not equal to the range of the StartingPoint.
0111   void Derivative(math_Matrix& Der) const;
0112 
0113   //! Returns the vector value of the error done on the
0114   //! functions at the root.
0115   //! Exception NotDone is raised if the root was not found.
0116   const math_Vector& FunctionSetErrors() const;
0117 
0118   //! Outputs the vector value of the error done on the
0119   //! functions at the root in Err.
0120   //! Exception NotDone is raised if the root was not found.
0121   //! Exception DimensionError is raised if the range of Err is
0122   //! not equal to the range of the StartingPoint.
0123   void FunctionSetErrors(math_Vector& Err) const;
0124 
0125   //! Returns the number of iterations really done
0126   //! during the computation of the Root.
0127   //! Exception NotDone is raised if the root was not found.
0128   int NbIterations() const;
0129 
0130   //! Prints information on the current state of the object.
0131   //! Is used to redefine the operator <<.
0132   Standard_EXPORT void Dump(Standard_OStream& o) const;
0133 
0134 protected:
0135   math_Vector        TolX;
0136   double             TolF;
0137   math_IntegerVector Indx;
0138   math_Vector        Scratch;
0139   math_Vector        Sol;
0140   math_Vector        DeltaX;
0141   math_Vector        FValues;
0142   math_Matrix        Jacobian;
0143 
0144 private:
0145   bool Done;
0146   int  State;
0147   int  Iter;
0148   int  Itermax;
0149 };
0150 
0151 #include <math_NewtonFunctionSetRoot.lxx>
0152 
0153 #endif // _math_NewtonFunctionSetRoot_HeaderFile