Method coeff

include/Eigen/Eigen/src/SparseCore/SparseMatrix.h:217–225

\returns the value of the matrix at position \a i, \a j * This function returns Scalar(0) if the element is an explicit \em zero */

    /** \returns the value of the matrix at position \a i, \a j
      * This function returns Scalar(0) if the element is an explicit \em zero */
    inline Scalar coeff(Index row, Index col) const
    {
      eigen_assert(row>=0 && row<rows() && col>=0 && col<cols());
      
      const Index outer = IsRowMajor ? row : col;
      const Index inner = IsRowMajor ? col : row;
      Index end = m_innerNonZeros ? m_outerIndex[outer] + m_innerNonZeros[outer] : m_outerIndex[outer+1];
      return m_data.atInRange(m_outerIndex[outer], end, inner);
    }

    /** \returns a non-const reference to the value of the matrix at position \a i, \a j
      *