用到的函数
extract()
例子
首先构造数据
week <- c("week1","week2","week3","week4")
value <- c(5,6,7,8)
data <- data.frame(week,value)
week value
1 week1 5
2 week2 6
3 week3 7
4 week4 8
extract(data,week,"week","(\\d)",convert = TRUE)
#(\\d)表示任意数字，将data中的week列从“week”后面找到任意数字，convert = TRUE表示转化为整数类型
week value
1 1 5
2 2 6
3 3 7
4 4 8
下面是验证上面参数convert的作用
a <- extract(data,week,"week","(\\d)",convert = TRUE)
class(a$week)
#[1] "integer"