如何将因子转换为数值？

Question

I'm analyzing data to University, and i dont know how to convert factor like: 58.4 [57.4-60.3] to numeric

I did :

data$male <- as.character(data$male)
data$male <- as.numeric(data$male)

but it doesnt work.

Warning message: NAs introduced by coercion

Could you help me with this problem ?

Answer 1

我们可以将一个或多个空格（ \\\\s+ ）后跟其他字符匹配到末尾，并将其替换为sub "" ，然后转换为numeric

data$male <- as.numeric(sub("\\s+.*", "", data$male))