1、测试数据
a <- c(8,4,7,6,2,5)
2、最大值、最小值
> max(a)
[1] 8
> min(a)
[1] 2
3、平均数、中位数
> mean(a)
[1] 5.333333
> median(a)
[1] 5.5
4、方差、标准差
> var(a)
[1] 4.666667
> sd(a)
[1] 2.160247
5、相关系数、协方差
> cor(a,log(a))
[1] 0.9778993
> cov(a,log(a))
[1] 1.057501
6、NA的处理
> a <- c(8,4,7,6,2,5)
> mean(a)
[1] 5.333333
> a <- c(8,4,7,6,NA,2,5)
> mean(a)
[1] NA
> mean(a,na.rm=TRUE)
[1] 5.333333
> a <- c(8,4,7,6,NA,2,5)
> mean(a)
[1] NA
> is.na(a)
[1] FALSE FALSE FALSE FALSE TRUE FALSE FALSE
> a[is.na(a)]
[1] NA
> a[is.na(a)] <- 0
> a
[1] 8 4 7 6 0 2 5
> mean(a)
[1] 4.571429
参考：https://www.cnblogs.com/liuchangchun/p/4456147.html