Mirror extending and circular spline function for empirical mode decomposition method

The Mirror Extending (ME) approach is proposed in this paper for solving the end extending issue in the Empirical Mode Decomposition (EMD) method. By this approach, the data extended into a closed circuit without end. The derivatives on ends are not necessary any more for Spline fingth. The approach eliminates the possible problems in reliability and uniqueness in the original extending approach of the EMD method. In the ME approach only one extending is necessary before the data analysis. A tipient criterion is proposed here for checking the extending approach. ME approach has been proved to satisy the theoretical criterion automatically and permanently. This approach makes the EMD method reliable and casy to follow.