R简单统计计算--笔记

#read  csv
specie28=read.csv(file="filename.csv")
#read txt
specie28=read.table("filename.txt", head=TRUE, sep=",")
#one attribute of specie28
height=specie28$HEIGHT
DBH=specie28$DBH
#mean of height 均值
height_m=mean(specie28$HEIGHT)
#maximum of height 最大值
height_max=max(specie28$HEIGHT)
#minimum of height 最小值
height_min=min(specie28$HEIGHT)
#standard deviation 标准差
height_sd=sd(specie28$HEIGHT)
#median 中值
height_median(specie28$HEIGHT)
#variance 方差
height_var=var(specie28$HEIGHT)
#两个变量之间的相关系数
cor(specie28$HEIGHT,log(specie28$HEIGHT))
#两个变量之间的协方差
cov(specie28$HEIGHT,log(specie28$HEIGHT))