canoco5该软件主要用于群落排序：就是把一个地区内所调查的群落样地（物种），按照相似度来排定各样地的位序，从而分析各样地（物种）之间及其与环境之间的相互关系。-canoco5The software is mainly used for sorting communities: that is the one area communities surveyed plot (species), according to the similarity to schedule plots bit

该函数返回值为积分结果，形参a,b分别为积分上下限，fun是被积函数。该函数用来求积分值。-This function returns a value of the integration result, parameters a, b is the integral upper and lower limits, respectively, fun is the plot function. This function is used to find the integral value