1 // Created on: 1991-05-13 2 // Created by: Laurent PAINNOT 3 // Copyright (c) 1991-1999 Matra Datavision 4 // Copyright (c) 1999-2014 OPEN CASCADE SAS 5 // 6 // This file is part of Open CASCADE Technology software library. 7 // 8 // This library is free software; you can redistribute it and/or modify it under 9 // the terms of the GNU Lesser General Public License version 2.1 as published 10 // by the Free Software Foundation, with special exception defined in the file 11 // OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT 12 // distribution for complete text of the license and disclaimer of any warranty. 13 // 14 // Alternatively, this file may be used under the terms of Open CASCADE 15 // commercial license or contractual agreement. 16 17 #ifndef _math_Gauss_HeaderFile 18 #define _math_Gauss_HeaderFile 19 20 #include <Standard.hxx> 21 #include <Standard_DefineAlloc.hxx> 22 #include <Standard_Handle.hxx> 23 24 #include <Standard_Boolean.hxx> 25 #include <math_Matrix.hxx> 26 #include <math_IntegerVector.hxx> 27 #include <Standard_Real.hxx> 28 #include <math_Vector.hxx> 29 #include <Standard_OStream.hxx> 30 #include <Message_ProgressRange.hxx> 31 32 class math_NotSquare; 33 class Standard_DimensionError; 34 class StdFail_NotDone; 35 class math_Matrix; 36 37 //! This class implements the Gauss LU decomposition (Crout algorithm) 38 //! with partial pivoting (rows interchange) of a square matrix and 39 //! the different possible derived calculation : 40 //! - solution of a set of linear equations. 41 //! - inverse of a matrix. 42 //! - determinant of a matrix. 43 class math_Gauss 44 { 45 public: 46 47 DEFINE_STANDARD_ALLOC 48 49 //! Given an input n X n matrix A this constructor performs its LU 50 //! decomposition with partial pivoting (interchange of rows). 51 //! This LU decomposition is stored internally and may be used to 52 //! do subsequent calculation. 53 //! If the largest pivot found is less than MinPivot the matrix A is 54 //! considered as singular. 55 //! Exception NotSquare is raised if A is not a square matrix. 56 Standard_EXPORT math_Gauss(const math_Matrix& A, 57 const Standard_Real MinPivot = 1.0e-20, 58 const Message_ProgressRange& theProgress = Message_ProgressRange()); 59 60 //! Returns true if the computations are successful, otherwise returns false IsDone() const61 Standard_Boolean IsDone() const { return Done; } 62 63 //! Given the input Vector B this routine returns the solution X of the set 64 //! of linear equations A . X = B. 65 //! Exception NotDone is raised if the decomposition of A was not done 66 //! successfully. 67 //! Exception DimensionError is raised if the range of B is not 68 //! equal to the number of rows of A. 69 Standard_EXPORT void Solve (const math_Vector& B, math_Vector& X) const; 70 71 //! Given the input Vector B this routine solves the set of linear 72 //! equations A . X = B. B is replaced by the vector solution X. 73 //! Exception NotDone is raised if the decomposition of A was not done 74 //! successfully. 75 //! Exception DimensionError is raised if the range of B is not 76 //! equal to the number of rows of A. 77 Standard_EXPORT void Solve (math_Vector& B) const; 78 79 //! This routine returns the value of the determinant of the previously LU 80 //! decomposed matrix A. 81 //! Exception NotDone may be raised if the decomposition of A was not done 82 //! successfully, zero is returned if the matrix A was considered as singular. 83 Standard_EXPORT Standard_Real Determinant() const; 84 85 //! This routine outputs Inv the inverse of the previously LU decomposed 86 //! matrix A. 87 //! Exception DimensionError is raised if the ranges of B are not 88 //! equal to the ranges of A. 89 Standard_EXPORT void Invert (math_Matrix& Inv) const; 90 91 //! Prints on the stream o information on the current state 92 //! of the object. 93 //! Is used to redefine the operator <<. 94 Standard_EXPORT void Dump (Standard_OStream& o) const; 95 96 protected: 97 98 math_Matrix LU; 99 math_IntegerVector Index; 100 Standard_Real D; 101 Standard_Boolean Done; 102 103 }; 104 operator <<(Standard_OStream & o,const math_Gauss & mG)105inline Standard_OStream& operator<<(Standard_OStream& o, const math_Gauss& mG) 106 { 107 mG.Dump(o); 108 return o; 109 } 110 111 #endif // _math_Gauss_HeaderFile 112