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
0029
0030 //! This class implements the Jacobi method to find the eigenvalues and
0031 //! the eigenvectors of a real symmetric square matrix.
0032 //! A sort of eigenvalues is done.
0033 class math_Jacobi
0034 {
0035 public:
0036
0037   DEFINE_STANDARD_ALLOC
0038
0039
0040
0041   //! Given a Real n X n matrix A, this constructor computes all its
0042   //! eigenvalues and eigenvectors using the Jacobi method.
0043   //! The exception NotSquare is raised if the matrix is not square.
0044   //! No verification that the matrix A is really symmetric is done.
0045   Standard_EXPORT math_Jacobi(const math_Matrix& A);
0046
0047   //! Returns true if the computations are successful, otherwise returns false.
0048     Standard_Boolean IsDone() const;
0049
0050   //! Returns the eigenvalues vector.
0051   //! Exception NotDone is raised if calculation is not done successfully.
0052     const math_Vector& Values() const;
0053
0054   //! returns the eigenvalue number Num.
0055   //! Eigenvalues are in the range (1..n).
0056   //! Exception NotDone is raised if calculation is not done successfully.
0057     Standard_Real Value (const Standard_Integer Num) const;
0058
0059   //! returns the eigenvectors matrix.
0060   //! Exception NotDone is raised if calculation is not done successfully.
0061     const math_Matrix& Vectors() const;
0062
0063   //! Returns the eigenvector V of number Num.
0064   //! Eigenvectors are in the range (1..n).
0065   //! Exception NotDone is raised if calculation is not done successfully.
0066     void Vector (const Standard_Integer Num, math_Vector& V) const;
0067
0068   //! Prints information on the current state of the object.
0069   //! Is used to redefine the operator <<.
0070   Standard_EXPORT void Dump (Standard_OStream& o) const;
0071
0072
0073
0074
0075 protected:
0076
0077
0078
0079
0080
0081 private:
0082
0083
0084
0085   Standard_Boolean Done;
0086   math_Matrix AA;
0087   Standard_Integer NbRotations;
0088   math_Vector EigenValues;
0089   math_Matrix EigenVectors;
0090
0091
0092 };
0093
0094
0095 #include <math_Jacobi.lxx>
0096
0097
0098
0099
0100
0101 #endif // _math_Jacobi_HeaderFile