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occt/src/math/math_Gauss.hxx
2019-03-13 16:39:43 +03:00

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4.0 KiB
C++

// Created on: 1991-05-13
// 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_Gauss_HeaderFile
#define _math_Gauss_HeaderFile
#include <Standard.hxx>
#include <Standard_DefineAlloc.hxx>
#include <Standard_Handle.hxx>
#include <Standard_Boolean.hxx>
#include <math_Matrix.hxx>
#include <math_IntegerVector.hxx>
#include <Standard_Real.hxx>
#include <math_Vector.hxx>
#include <Standard_OStream.hxx>
class math_NotSquare;
class Standard_DimensionError;
class StdFail_NotDone;
class math_Matrix;
class Message_ProgressIndicator;
//! This class implements the Gauss LU decomposition (Crout algorithm)
//! with partial pivoting (rows interchange) of a square matrix and
//! the different possible derived calculation :
//! - solution of a set of linear equations.
//! - inverse of a matrix.
//! - determinant of a matrix.
class math_Gauss
{
public:
DEFINE_STANDARD_ALLOC
//! Given an input n X n matrix A this constructor performs its LU
//! decomposition with partial pivoting (interchange of rows).
//! This LU decomposition is stored internally and may be used to
//! do subsequent calculation.
//! If the largest pivot found is less than MinPivot the matrix A is
//! considered as singular.
//! Exception NotSquare is raised if A is not a square matrix.
Standard_EXPORT math_Gauss(const math_Matrix& A,
const Standard_Real MinPivot = 1.0e-20,
const Handle(Message_ProgressIndicator) & aProgress = Handle(Message_ProgressIndicator)());
//! Returns true if the computations are successful, otherwise returns false
Standard_Boolean IsDone() const { return Done; }
//! Given the input Vector B this routine returns the solution X of the set
//! of linear equations A . X = B.
//! Exception NotDone is raised if the decomposition of A was not done
//! successfully.
//! Exception DimensionError is raised if the range of B is not
//! equal to the number of rows of A.
Standard_EXPORT void Solve (const math_Vector& B, math_Vector& X) const;
//! Given the input Vector B this routine solves the set of linear
//! equations A . X = B. B is replaced by the vector solution X.
//! Exception NotDone is raised if the decomposition of A was not done
//! successfully.
//! Exception DimensionError is raised if the range of B is not
//! equal to the number of rows of A.
Standard_EXPORT void Solve (math_Vector& B) const;
//! This routine returns the value of the determinant of the previously LU
//! decomposed matrix A.
//! Exception NotDone may be raised if the decomposition of A was not done
//! successfully, zero is returned if the matrix A was considered as singular.
Standard_EXPORT Standard_Real Determinant() const;
//! This routine outputs Inv the inverse of the previously LU decomposed
//! matrix A.
//! Exception DimensionError is raised if the ranges of B are not
//! equal to the ranges of A.
Standard_EXPORT void Invert (math_Matrix& Inv) const;
//! Prints on the stream o information on the current state
//! of the object.
//! Is used to redefine the operator <<.
Standard_EXPORT void Dump (Standard_OStream& o) const;
protected:
math_Matrix LU;
math_IntegerVector Index;
Standard_Real D;
Standard_Boolean Done;
};
inline Standard_OStream& operator<<(Standard_OStream& o, const math_Gauss& mG)
{
mG.Dump(o);
return o;
}
#endif // _math_Gauss_HeaderFile