按组添加ID列
按组添加ID列
提问于 2012-11-26 22:10:37
我想在R中创建一个基于纬度和经度两列的唯一ID，以便重复的位置具有相同的集群ID。
例如：
LAT LONG Cluster_ID
13.5330 -15.4180 1
13.5330 -15.4180 1
13.5330 -15.4180 1
13.5330 -15.4180 1
13.5330 -15.4170 2
13.5330 -15.4170 2
13.5330 -15.4170 2
13.5340 -14.9350 3
13.5340 -14.9350 3
13.5340 -15.9170 4
13.3670 -14.6190 5回答 4
Stack Overflow用户
回答已采纳
发布于 2012-11-26 22:22:12
这里有一种使用interaction的方法。
d <- read.table(text='LAT LONG
13.5330 -15.4180
13.5330 -15.4180
13.5330 -15.4180
13.5330 -15.4180
13.5330 -15.4170
13.5330 -15.4170
13.5330 -15.4170
13.5340 -14.9350
13.5340 -14.9350
13.5340 -15.9170
13.3670 -14.6190', header=TRUE)
d <- transform(d, Cluster_ID = as.numeric(interaction(LAT, LONG, drop=TRUE)))
# LAT LONG Cluster_ID
# 1 13.533 -15.418 2
# 2 13.533 -15.418 2
# 3 13.533 -15.418 2
# 4 13.533 -15.418 2
# 5 13.533 -15.417 3
# 6 13.533 -15.417 3
# 7 13.533 -15.417 3
# 8 13.534 -14.935 4
# 9 13.534 -14.935 4
# 10 13.534 -15.917 1
# 11 13.367 -14.619 5编辑:整合了@Spacedman的建议，向interaction提供drop=TRUE。
Stack Overflow用户
发布于 2012-11-26 22:24:10
数据：
dat <- read.table(text="
LAT LONG
13.5330 -15.4180
13.5330 -15.4180
13.5330 -15.4180
13.5330 -15.4180
13.5330 -15.4170
13.5330 -15.4170
13.5330 -15.4170
13.5340 -14.9350
13.5340 -14.9350
13.5340 -15.9170
13.3670 -14.6190", header = TRUE)这些命令创建以1开头的id变量：
comb <- with(dat, paste(LAT, LONG))
within(dat, Cluster_ID <- match(comb, unique(comb)))输出：
LAT LONG Cluster_ID
1 13.533 -15.418 1
2 13.533 -15.418 1
3 13.533 -15.418 1
4 13.533 -15.418 1
5 13.533 -15.417 2
6 13.533 -15.417 2
7 13.533 -15.417 2
8 13.534 -14.935 3
9 13.534 -14.935 3
10 13.534 -15.917 4
11 13.367 -14.619 5Stack Overflow用户
发布于 2012-11-27 12:52:04
data.table 1.8.3中添加了.GRP，允许您执行以下操作：
# Your data, as a data.frame
dat <- read.table(text='LAT LONG
13.5330 -15.4180
13.5330 -15.4180
13.5330 -15.4180
13.5330 -15.4180
13.5330 -15.4170
13.5330 -15.4170
13.5330 -15.4170
13.5340 -14.9350
13.5340 -14.9350
13.5340 -15.9170
13.3670 -14.6190', header=TRUE)
# Convert it to a data.table
# with keys as the combination of LAT and LONG
library(data.table)
DT <- data.table(dat, key="LAT,LONG")
DT[, Cluster_ID:=.GRP, by=key(DT)]
DT
# LAT LONG Cluster_ID
# 1: 13.367 -14.619 1
# 2: 13.533 -15.418 2
# 3: 13.533 -15.418 2
# 4: 13.533 -15.418 2
# 5: 13.533 -15.418 2
# 6: 13.533 -15.417 3
# 7: 13.533 -15.417 3
# 8: 13.533 -15.417 3
# 9: 13.534 -15.917 4
# 10: 13.534 -14.935 5
# 11: 13.534 -14.935 5页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/13566562
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