Method coeff

include/Eigen/src/SparseCore/SparseMatrix.h:211–218

\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.
   *