summeryang
在R语言实战中有命令
attach(mtcars)
cor(mtcars)
报错:Error in cor(mtcars) : 'x' must be numeric
查看mtcars列表中各个变量都是数值型
转换后
> x <- mtcars[,c("mpg","cyl","disp","hp","drat","wt","qsec","vs","am","gear","carb")]
> y <- mtcars[,c("mpg","cyl","disp","hp","drat","wt","qsec","vs","am","gear","carb")]
> cor(x,y)可以得出结果
然后
is.numeric(mtcars)
[1] FALSE
可是书上给的例子确是cor(mtcars),这是为什么呢?