include/opencascade/math_Jacobi.hxx

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_Jacobi_HeaderFile
0018 #define _math_Jacobi_HeaderFile
0019
0020 #include <Standard.hxx>
0021 #include <Standard_DefineAlloc.hxx>
0022 #include <Standard_Handle.hxx>
0023
0024 #include <math_Matrix.hxx>
0025 #include <math_Vector.hxx>
0026 #include <Standard_OStream.hxx>
0027
0028 //! This class implements the Jacobi method to find the eigenvalues and
0029 //! the eigenvectors of a real symmetric square matrix.
0030 //! A sort of eigenvalues is done.
0031 class math_Jacobi
0032 {
0033 public:
0034   DEFINE_STANDARD_ALLOC
0035
0036   //! Given a Real n X n matrix A, this constructor computes all its
0037   //! eigenvalues and eigenvectors using the Jacobi method.
0038   //! The exception NotSquare is raised if the matrix is not square.
0039   //! No verification that the matrix A is really symmetric is done.
0040   Standard_EXPORT math_Jacobi(const math_Matrix& A);
0041
0042   //! Returns true if the computations are successful, otherwise returns false.
0043   Standard_Boolean IsDone() const;
0044
0045   //! Returns the eigenvalues vector.
0046   //! Exception NotDone is raised if calculation is not done successfully.
0047   const math_Vector& Values() const;
0048
0049   //! returns the eigenvalue number Num.
0050   //! Eigenvalues are in the range (1..n).
0051   //! Exception NotDone is raised if calculation is not done successfully.
0052   Standard_Real Value(const Standard_Integer Num) const;
0053
0054   //! returns the eigenvectors matrix.
0055   //! Exception NotDone is raised if calculation is not done successfully.
0056   const math_Matrix& Vectors() const;
0057
0058   //! Returns the eigenvector V of number Num.
0059   //! Eigenvectors are in the range (1..n).
0060   //! Exception NotDone is raised if calculation is not done successfully.
0061   void Vector(const Standard_Integer Num, math_Vector& V) const;
0062
0063   //! Prints information on the current state of the object.
0064   //! Is used to redefine the operator <<.
0065   Standard_EXPORT void Dump(Standard_OStream& o) const;
0066
0067 protected:
0068 private:
0069   Standard_Boolean Done;
0070   math_Matrix      AA;
0071   Standard_Integer NbRotations;
0072   math_Vector      EigenValues;
0073   math_Matrix      EigenVectors;
0074 };
0075
0076 #include <math_Jacobi.lxx>
0077
0078 #endif // _math_Jacobi_HeaderFile