Method setZero

include/Eigen/Eigen/src/SparseCore/SparseMatrix.h:288–295

Removes all non zeros but keep allocated memory * * This function does not free the currently allocated memory. To release as much as memory as possible, * call \code mat.data().squeeze(); \endcode after resizing it. * * \sa resize(Index,Index), data() */

      * \sa resize(Index,Index), data()
      */
    inline void setZero()
    {
      m_data.clear();
      std::fill_n(m_outerIndex, m_outerSize + 1, StorageIndex(0));
      if(m_innerNonZeros) {
        std::fill_n(m_innerNonZeros, m_outerSize, StorageIndex(0));
      }
    }

    /** Preallocates \a reserveSize non zeros.
      *