solveLinear() [1/2]

bool ffpackInterface::solveLinear	(	const DMatZZpFFPACK &	A,
		const DMatZZpFFPACK &	B,
		bool	right_side,
		DMatZZpFFPACK &	X,
		bool	declare_A_is_invertible )

Definition at line 183 of file dmat.cpp.

{
  //    std::cerr << "inside FFpackSolveLinear" << std::endl;
  (void) declare_A_is_invertible;
  size_t a_rows = A.numRows();
  size_t a_cols = A.numColumns();
 
  size_t b_rows = B.numRows();
  size_t b_cols = B.numColumns();
 
  DMatZZpFFPACK copyA(A);
  DMatZZpFFPACK copyB(B);
 
  // preallocate the space for the solutions:
  size_t x_rows = (right_side ? a_cols : b_rows);
  size_t x_cols = (right_side ? b_cols : a_rows);
 
  X.resize(x_rows, x_cols);  // sets it to 0 too.
 
  int info = 0;  // >0 if the system is inconsistent, ==0 means success
 
  FFPACK::fgesv(A.ring().field(),
                (right_side ? FFLAS::FflasLeft : FFLAS::FflasRight),
                a_rows,
                a_cols,
                (right_side ? b_cols : b_rows),
                copyA.rowMajorArray(),
                a_cols,  // leading dim of A
                X.rowMajorArray(),
                x_cols,
                copyB.rowMajorArray(),
                b_cols,
                &info);
 
  if (info > 0)
    {
      // the system is inconsistent
      return false;
    }
 
  return true;
}

References DMatZZpFFPACK.