Supplement 1. R source code for functions and examples of selection ratio analysis on community aggregated traits (SRCAT).

File List
srcat.R -- R source code to run SRCAT analyses

srcat_examples.R -- R source code to run SRCAT examples

Description
The function srcat() calculates the probability that a site i will select state j from k alternative versions of a discrete trait. If a continuous trait is supplied, a discrete approximation is used to estimate the selective filter imposed by i as a probability function of the trait value. Both estimations are accomplished using data on species (relative) abundance at sites (S), species possession of trait states (W), and the expected availability of species to sites, assuming no trait-based selection (A). Function parameters are described in comments within the script. The script file srcat_examples.R runs several examples of SRCAT analysis using both discrete and continuous traits.

文件清单
srcat.R：用于执行SRCAT分析的R源代码

srcat_examples.R：用于运行SRCAT示例的R源代码

描述
srcat()函数用于计算样点i从某一离散性状的k个可选状态中选择状态j的概率。当输入为连续性状时，将通过离散化近似的方法，基于性状值的概率函数来估算样点i所施加的选择过滤作用。两种估算均基于以下三类数据：样点处的物种（相对）多度（记为S）、物种所具有的性状状态（记为W），以及假设不存在基于性状的选择时，物种在各样点的预期可获得性（记为A）。脚本内的注释已对函数参数进行说明。脚本文件srcat_examples.R提供了分别使用离散性状与连续性状开展SRCAT分析的多个示例。