Mann-Kendall 趋势分析，于进行m-k检验 突变所发生的时间-Mann-Kendall，used for testing mk mutation occurred at a time

Mann-Kendall Tau-b非线性函数，用于时间序列分析中计算平均变化趋势。-The Mann-Kendall Tau-b non-parametric function computes a coefficient representing strength and direction of a trend for equally spaced data. While you do not need the Statistic

计算mann-kendall 进行时间序列分析-calculate mann-kendall