创建连续值的组名 [英] Create group names for consecutive values

问题描述

看起来很简单，却找不到简单的方法.我在下面有一个x向量，需要为连续的值创建组名.我的尝试是使用rle，更好的主意吗?

Looks like an easy task, can't figure out a simpler way. I have an x vector below, and need to create group names for consecutive values. My attempt was using rle, better ideas?

# data
x <- c(1,1,1,2,2,2,3,2,2,1,1)

# make groups
rep(paste0("Group_", 1:length(rle(x)$lengths)), rle(x)$lengths)
# [1] "Group_1" "Group_1" "Group_1" "Group_2" "Group_2" "Group_2" "Group_3" "Group_4"
# [9] "Group_4" "Group_5" "Group_5"

推荐答案

使用diff和cumsum:

paste0("Group_", cumsum(c(1, diff(x) != 0)))
#[1] "Group_1" "Group_1" "Group_1" "Group_2" "Group_2" "Group_2" "Group_3" "Group_4" "Group_4" "Group_5" "Group_5"

(如果您的值是浮点值，则可能必须避免使用!=并改用公差).

(If your values are floating point values, you might have to avoid != and use a tolerance instead.)

这篇关于创建连续值的组名的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！