OCCT

// Copyright (c) 1997-1999 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 OCCT_DEBUG
#define No_Standard_RangeError
#define No_Standard_OutOfRange
#define No_Standard_DimensionError

// #endif

#include <math_GaussLeastSquare.hxx>
#include <math_Matrix.hxx>
#include <math_Recipes.hxx>
#include <Standard_DimensionError.hxx>
#include <StdFail_NotDone.hxx>

math_GaussLeastSquare::math_GaussLeastSquare(const math_Matrix& A, const double MinPivot)
    : LU(1, A.ColNumber(), 1, A.ColNumber()),
      A2(1, A.ColNumber(), 1, A.RowNumber()),
      Index(1, A.ColNumber())
{
  A2 = A.Transposed();
  LU.Multiply(A2, A);

  int Error = LU_Decompose(LU, Index, D, MinPivot);
  Done      = Error == 0;
}

void math_GaussLeastSquare::Solve(const math_Vector& B, math_Vector& X) const
{
  StdFail_NotDone_Raise_if(!Done, " ");
  Standard_DimensionError_Raise_if((B.Length() != A2.ColNumber()) || (X.Length() != A2.RowNumber()),
                                   " ");

  X.Multiply(A2, B);

  LU_Solve(LU, Index, X);
}

void math_GaussLeastSquare::Dump(Standard_OStream& o) const
{

  o << "math_GaussLeastSquare ";
  if (Done)
  {
    o << " Status = Done \n";
  }
  else
  {
    o << "Status = not Done \n";
  }
}