setUpperLower()

template<class RingType>

void LUUtil< RingType >::setUpperLower ( const Mat & LU, Mat & lower, Mat & upper )

static

Definition at line 414 of file dmat-lu-inplace.hpp.

{
  size_t min = std::min(LU.numRows(), LU.numColumns());
  lower.resize(LU.numRows(), min);
  upper.resize(min, LU.numColumns());
 
  // At this point, lower and upper should be zero matrices.
  assert(MatrixOps::isZero(lower));
  assert(MatrixOps::isZero(upper));
 
  for (size_t c = 0; c < LU.numColumns(); c++)
    {
      if (c < min) LU.ring().set_from_long(lower.entry(c, c), 1);
      for (size_t r = 0; r < LU.numRows(); r++)
        {
          if (r <= c)
            LU.ring().set(upper.entry(r, c), LU.entry(r, c));
          else if (c < lower.numRows())
            {
              LU.ring().set(lower.entry(r, c), LU.entry(r, c));
            }
        }
    }
}

References DMat< ACoeffRing >::entry(), MatrixOps::isZero(), DMat< ACoeffRing >::numRows(), and DMat< ACoeffRing >::resize().

Referenced by DMatLinAlg< M2::ARingQQ >::matrixPLU(), DMatLinAlg< M2::ARingZZpFFPACK >::matrixPLU(), and DMatLinAlg< M2::ARingZZpFlint >::matrixPLU().