按定义的间隔切割答案

【问题标题】：Cut by Defined Interval按定义的间隔切割
【发布时间】：2011-08-10 10:23:02
【问题描述】：

R 中是否有某种方法可以在不中断的情况下按定义的间隔进行切割？

例如，如果我想要精确区间 [1,10] 中的值；默认情况下，cut 会将这个区间分成更小的区间。

【问题讨论】：

标签： r

【解决方案1】：

要切割到预定义的间隔，您可以使用breaks 参数指定中断向量。

定义一些数据：

x <- sample(0:20, 100, replace=TRUE)
x

现在在 0、10 和 20 处切割 x：

cut(x, breaks=c(0, 10, 20), include.lowest=TRUE)

  [1] (10,20] [0,10]  [0,10]  (10,20] (10,20] (10,20] [0,10]  (10,20] (10,20]
 [10] (10,20] [0,10]  (10,20] (10,20] (10,20] [0,10]  (10,20] [0,10]  [0,10] 
 [19] [0,10]  (10,20] [0,10]  [0,10]  [0,10]  (10,20] [0,10]  (10,20] (10,20]
 [28] (10,20] (10,20] [0,10]  [0,10]  [0,10]  [0,10]  (10,20] [0,10]  [0,10] 
 [37] [0,10]  [0,10]  (10,20] (10,20] (10,20] (10,20] [0,10]  (10,20] [0,10] 
 [46] (10,20] [0,10]  (10,20] (10,20] [0,10]  [0,10]  (10,20] (10,20] (10,20]
 [55] [0,10]  [0,10]  (10,20] [0,10]  [0,10]  [0,10]  [0,10]  (10,20] (10,20]
 [64] (10,20] [0,10]  [0,10]  (10,20] (10,20] (10,20] (10,20] (10,20] (10,20]
 [73] (10,20] [0,10]  [0,10]  [0,10]  (10,20] [0,10]  (10,20] [0,10]  (10,20]
 [82] [0,10]  [0,10]  (10,20] [0,10]  [0,10]  [0,10]  (10,20] (10,20] [0,10] 
 [91] [0,10]  [0,10]  (10,20] (10,20] [0,10]  [0,10]  [0,10]  [0,10]  (10,20]
[100] (10,20]
Levels: [0,10] (10,20]

【讨论】：

我有一个与 'cut' 相关的问题 cut(x$mpg,4) 给了我级别：(10.4,16.3] (16.3,22.1] (22.1,28] (28,33.9) 如何我们可以提取分界点吗？这里的分界点是10.4,16.3,22.1,28,33.9
@darkage 这是一个不同的问题，与原始问题没有真正的关系。但是你的问题在?cut 的最后一个例子中得到了回答。如果这没有帮助，请提出一个新问题。

【解决方案2】：

这样的？从 0 到 1 每 0.2 中断一次。

> a <- runif(100)
> cut(a, seq(from = 0, to = 1, by = 0.2))
  [1] (0,0.2]   (0.8,1]   (0.8,1]   (0.6,0.8] (0.6,0.8] (0,0.2]   (0.6,0.8]
  [8] (0.2,0.4] (0.8,1]   (0.4,0.6] (0.8,1]   (0.4,0.6] (0.8,1]   (0.6,0.8]
 [15] (0.8,1]   (0,0.2]   (0.8,1]   (0.8,1]   (0.6,0.8] (0.6,0.8] (0.2,0.4]
 [22] (0.4,0.6] (0.6,0.8] (0.2,0.4] (0.6,0.8] (0.6,0.8] (0.6,0.8] (0,0.2]  
 [29] (0,0.2]   (0.2,0.4] (0,0.2]   (0,0.2]   (0,0.2]   (0,0.2]   (0,0.2]  
 [36] (0.6,0.8] (0.2,0.4] (0.6,0.8] (0.6,0.8] (0.8,1]   (0.2,0.4] (0.4,0.6]
 [43] (0.4,0.6] (0.6,0.8] (0.2,0.4] (0.6,0.8] (0.6,0.8] (0.6,0.8] (0.4,0.6]
 [50] (0.6,0.8] (0.6,0.8] (0,0.2]   (0.2,0.4] (0.8,1]   (0.8,1]   (0.8,1]  
 [57] (0.6,0.8] (0.2,0.4] (0.2,0.4] (0,0.2]   (0.8,1]   (0.8,1]   (0.2,0.4]
 [64] (0.8,1]   (0.2,0.4] (0.4,0.6] (0.8,1]   (0,0.2]   (0.4,0.6] (0,0.2]  
 [71] (0.4,0.6] (0.8,1]   (0.6,0.8] (0.4,0.6] (0,0.2]   (0.2,0.4] (0.4,0.6]
 [78] (0,0.2]   (0.2,0.4] (0.8,1]   (0,0.2]   (0.4,0.6] (0.8,1]   (0,0.2]  
 [85] (0,0.2]   (0.2,0.4] (0.2,0.4] (0.4,0.6] (0.8,1]   (0.2,0.4] (0,0.2]  
 [92] (0.6,0.8] (0.2,0.4] (0.2,0.4] (0.8,1]   (0.2,0.4] (0.4,0.6] (0,0.2]  
 [99] (0,0.2]   (0,0.2]  
Levels: (0,0.2] (0.2,0.4] (0.4,0.6] (0.6,0.8] (0.8,1]

【讨论】：