Function conservativeResize

include/Eigen/src/SparseCore/SparseVector.h:246–253

Resizes the sparse vector to \a newSize, while leaving old values untouched. * * If the size of the vector is decreased, then the storage of the out-of bounds coefficients is kept and reserved. * Call .data().squeeze() to free extra memory. * * \sa reserve(), setZero() */

   * \sa reserve(), setZero()
   */
  void conservativeResize(Index newSize) {
    if (newSize < m_size) {
      Index i = 0;
      while (i < m_data.size() && m_data.index(i) < newSize) ++i;
      m_data.resize(i);
    }
    m_size = newSize;
  }

  void resizeNonZeros(Index size) { m_data.resize(size); }