EMD端点效应参考代码，包含多个算法：极值平均，边界特征尺度延拓，极值延拓，基于ISBM延拓，平行延拓，镜像延拓-EMD end effect reference code contains multiple algorithms: extreme average, the boundary characteristic scale extension, extreme extension, extension based ISBM parallel extension, mirror exte

本算法在左右只延拓极大极小值点各一个， isbm是判断是否进行isbm的算法，默认进行sbm而非isbm，默认进行isbm算法了(In this algorithm, an isbm algorithm is used to determine whether isbm is performed, and isbm is used by default)