根据另一个数据框中的值汇总一个数据框中的数据

Question

我有两个数据框，一个包含调查日期的详细信息，另一个包含正在记录的个人实例。如下：

Records <- data.frame("Location"=c("A","A","B","C","C","C","D"),
                      "Date"= c("09/01/2017","12/01/2017","20/01/2017","06/06/2017","03/06/2017","19/01/2017","02/01/2017"),
                      "Individuals"= c(3,2,6,4,0,1,6))
Surveys <- data.frame("Location"=c("A","B","C","D","A","B","C","D"),
                     "Start"= c(rep("01/01/2017",length=4),rep("01/06/2017",length=4)),
                      "End"= c(rep("01/02/2017",length=4),rep("01/07/2017",length=4)))

> Surveys
  Location      Start        End
1        A 01/01/2017 01/02/2017
2        B 01/01/2017 01/02/2017
3        C 01/01/2017 01/02/2017
4        D 01/01/2017 01/02/2017
5        A 01/06/2017 01/07/2017
6        B 01/06/2017 01/07/2017
7        C 01/06/2017 01/07/2017
8        D 01/06/2017 01/07/2017
> Records
  Location       Date Individuals
1        A 09/01/2017           3
2        A 12/01/2017           2
3        B 20/01/2017           6
4        C 06/06/2017           4
5        C 03/06/2017           0
6        C 19/01/2017           1
7        D 02/01/2017           6

我希望在调查数据框中添加一列，汇总在该站点和相关时间段内发生的个人数量。结果如下所示：

Sum.Individuals <- c(5,6,1,6,0,0,4,0)
Final <- cbind(Surveys,Sum.Individuals)

> Final
  Location      Start        End Total.Individuals
1        A 01/01/2017 01/02/2017                 5
2        B 01/01/2017 01/02/2017                 6
3        C 01/01/2017 01/02/2017                 1
4        D 01/01/2017 01/02/2017                 6
5        A 01/06/2017 01/07/2017                 0
6        B 01/06/2017 01/07/2017                 0
7        C 01/06/2017 01/07/2017                 4
8        D 01/06/2017 01/07/2017                 0

我希望这是有道理的，任何帮助表示赞赏。

干杯

Answer 1

我会建议以下步骤：

1. 在位置上加入两个表
2. 过滤日期在开始和结束之间的位置
3. 按位置、开始和结束分组；总结个人。

可能是这样的：

library(tidyverse)
library(magrittr)
df <- inner_join(surveys,records,by='Location')
df %<>% filter(Date >= Start, Date <= End)
df %<>% group_by(Location,Start,End) %>% summarise(totalindividuals=sum(individuals)

希望对您有所帮助。如果您发现代码令人困惑，您可能希望探索加入和过滤的概念，以及通常与此类任务非常相关的 dplyr 包。