如何将向量分成规则的连续序列组？ [英] How to partition a vector into groups of regular, consecutive sequences?

问题描述

我有一个向量，例如 c（1、3、4、5、9、10、17、29、30），我想分组

I have a vector, such as c(1, 3, 4, 5, 9, 10, 17, 29, 30) and I would like to group together the 'neighboring' elements that form a regular, consecutive sequence in a ragged vector resulting in:

L1：1

L2：3,4，在衣衫vector的向量中形成规则连续序列的邻居元素， 5

L3：9,10

L4：17

L5：29,30

L1: 1
L2: 3,4,5
L3: 9,10
L4: 17
L5: 29,30

（前C程序员的）天真代码：

Naive code (of an ex-C programmer):

partition.neighbors <- function(v)
{
    result <<- list() #jagged array
    currentList <<- v[1] #current series

    for(i in 2:length(v))
    {
        if(v[i] - v [i-1] == 1)
        {
            currentList <<- c(currentList, v[i])
        }
        else
        {
            result <<- c(result, list(currentList))
            currentList <<- v[i] #next series
        }       
    }

    return(result)  
}

现在我明白了，

a ）R不是C（尽管有花括号）
b）全局变量是纯邪恶的
c）这是获得结果的极其无效的方法

Now I understand that

a) R is not C (despite the curly brackets)
b) global variables are pure evil
c) that is a horribly inefficient way of achieving the result

，因此欢迎使用更好的解决方案。

, so any better solutions are welcome.

推荐答案

大量使用一些R惯用法：

Making heavy use of some R idioms:

> split(v, cumsum(c(1, diff(v) != 1)))
$`1`
[1] 1

$`2`
[1] 3 4 5

$`3`
[1]  9 10

$`4`
[1] 17

$`5`
[1] 29 30

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