Question

R.3.3.2

想象一个载体

a <- c(3,2,5,6,7,8,2,9)

我想将a归类为less or equal than 4和greater than 4。

当我使用table(a)

时

我需要获得如下结果：

less or equal than 4          greater than 4

3                               5

如何获得此结果？有什么建议吗？提前谢谢。

Answer 1

另一种选择是将cut功能与table结合使用：

table(cut(a, breaks = c(-Inf, 4, Inf), 
          labels = c('less and equal than 4','greater than 4'))
      )

给出：

less and equal than 4        greater than 4 
                    3                     5

Answer 2

为什么不使用

table(a>4)

Answer 3

您可以找到哪个值属于哪个组，并计算该组中的值数。

a <- c(3,2,5,6,7,8,2,9)
x <- data.frame(a, test = a <= 4,
                txt = ifelse(a <= 4, "less or equal to 4", "greater than 4"))
aggregate(a ~ test, data = x, length)

   test a
1 FALSE 5
2  TRUE 3

aggregate(a ~ txt, data = x, FUN = length)

                 txt a
1     greater than 4 5
2 less or equal to 4 3

第三种选择。

table(x$txt)

greater than 4 less or equal to 4 
                 5                  3

Answer 4

基于@Jaap答案，使用管道%>%也许更好一些。

虚拟数据：

a <- c(3,2,5,6,7,8,2,9)

# combine functions using pipes  %>% 

a %>%
  cut(breaks = c(-Inf, 4, Inf),
      labels = c('less and equal than 4','greater than 4')) %>%
  table

其中给出带有标签的结果：

less and equal than 4        greater than 4 
                    3                     5

如果您希望使用比例表，请在管道的末尾添加prop.table：

a %>%
  cut(breaks = c(-Inf, 4, Inf),
      labels = c('less and equal than 4','greater than 4')) %>%
  table %>%
  prop.table  # this was added

哪个给出结果：

less and equal than 4        greater than 4 
                0.375                 0.625

如何将数据分类到不同的级别？

4 个答案: