EIC code displayed by LXR master/​include/​opencascade/​math_Householder.hxx	Source navigation Diff markup Identifier search General search
	Version: master test Revert   Change

File indexing completed on 2026-09-14 09:15:08

 // Created on: 1991-08-07
 // Created by: Laurent PAINNOT
 // Copyright (c) 1991-1999 Matra Datavision
 // Copyright (c) 1999-2014 OPEN CASCADE SAS
 //
 // This file is part of Open CASCADE Technology software library.
 //
 // This library is free software; you can redistribute it and/or modify it under
 // the terms of the GNU Lesser General Public License version 2.1 as published
 // by the Free Software Foundation, with special exception defined in the file
 // OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT
 // distribution for complete text of the license and disclaimer of any warranty.
 //
 // Alternatively, this file may be used under the terms of Open CASCADE
 // commercial license or contractual agreement.
 
 #ifndef _math_Householder_HeaderFile
 #define _math_Householder_HeaderFile
 
 #include <Standard.hxx>
 #include <Standard_DefineAlloc.hxx>
 #include <Standard_Handle.hxx>
 
 #include <math_Matrix.hxx>
 #include <math_Vector.hxx>
 #include <Standard_OStream.hxx>
 
 //! This class implements the least square solution of a set of
 //! linear equations of m unknowns (n >= m) using the Householder
 //! method. It solves A.X = B.
 //! This algorithm has more numerical stability than
 //! GaussLeastSquare but is longer.
 //! It must be used if the matrix is singular or nearly singular.
 //! It is about 16% longer than GaussLeastSquare if there is only
 //! one member B to solve.
 //! It is about 30% longer if there are twenty B members to solve.
 class math_Householder
 {
 public:
   DEFINE_STANDARD_ALLOC
 
   //! Given an input matrix A with n>= m, given an input matrix B
   //! this constructor performs the least square resolution of
   //! the set of linear equations A.X = B for each column of B.
   //! If a column norm is less than EPS, the resolution can't
   //! be done.
   //! Exception DimensionError is raised if the row number of B
   //! is different from the A row number.
   Standard_EXPORT math_Householder(const math_Matrix& A,
                                    const math_Matrix& B,
                                    const double       EPS = 1.0e-20);
 
   //! Given an input matrix A with n>= m, given an input matrix B
   //! this constructor performs the least square resolution of
   //! the set of linear equations A.X = B for each column of B.
   //! If a column norm is less than EPS, the resolution can't
   //! be done.
   //! Exception DimensionError is raised if the row number of B
   //! is different from the A row number.
   Standard_EXPORT math_Householder(const math_Matrix& A,
                                    const math_Matrix& B,
                                    const int          lowerArow,
                                    const int          upperArow,
                                    const int          lowerAcol,
                                    const int          upperAcol,
                                    const double       EPS = 1.0e-20);
 
   //! Given an input matrix A with n>= m, given an input vector B
   //! this constructor performs the least square resolution of
   //! the set of linear equations A.X = B.
   //! If a column norm is less than EPS, the resolution can't
   //! be done.
   //! Exception DimensionError is raised if the length of B
   //! is different from the A row number.
   Standard_EXPORT math_Householder(const math_Matrix& A,
                                    const math_Vector& B,
                                    const double       EPS = 1.0e-20);
 
   //! Returns true if the computations are successful, otherwise returns false.
   bool IsDone() const;
 
   //! Given the integer Index, this routine returns the
   //! corresponding least square solution sol.
   //! Exception NotDone is raised if the resolution has not be
   //! done.
   //! Exception OutOfRange is raised if Index <=0 or
   //! Index is more than the number of columns of B.
   void Value(math_Vector& sol, const int Index = 1) const;
 
   //! Returns the matrix sol of all the solutions of the system
   //! A.X = B.
   //! Exception NotDone is raised is the resolution has not be
   //! done.
   const math_Matrix& AllValues() const;
 
   //! Prints information on the current state of the object.
   Standard_EXPORT void Dump(Standard_OStream& o) const;
 
 protected:
   //! This method is used internally for each constructor
   //! above and can't be used directly.
   Standard_EXPORT void Perform(const math_Matrix& A, const math_Matrix& B, const double EPS);
 
 private:
   math_Matrix Sol;
   math_Matrix Q;
   bool        Done;
   int         mylowerArow;
   int         myupperArow;
   int         mylowerAcol;
   int         myupperAcol;
 };
 
 #include <math_Householder.lxx>
 
 #endif // _math_Householder_HeaderFile

This page was automatically generated by the 2.3.7 LXR engine. The LXR team