r - 基于具有不同列名的 2 列合并 2 个数据框

Question

我有 2 个非常大的数据集，如下所示:

merge_data <- data.frame(ID = c(1,2,3,4,5,6,7,8,9,10), 
                         position=c("yes","no","yes","no","yes", 
                                    "no","yes","no","yes","yes"),
                         school = c("a","b","a","a","c","b","c","d","d","e"),
                         year1 = c(2000,2000,2000,2001,2001,2000,
                                   2003,2005,2008,2009), 
                         year2=year1-1)


 merge_data

 ID position school year1 year2
 1   1  support   a  2000  1999
 2   2   oppose   b  2000  1999
 3   3  support   a  2000  1999
 4   4   oppose   a  2001  2000
 5   5  support   c  2001  2000
 6   6   oppose   b  2000  1999
 7   7  support   c  2003  2002
 8   8   oppose   d  2005  2004
 9   9  support   d  2008  2007
 10 10  support   e  2009  2008



merge_data_2 <- data.frame(year=c(1999,1999,2000,2000,2000,2001,2003
                                  ,2012,2009,2009,2008,2002,2009,2005,
                                  2001,2000,2002,2000,2008,2005),
                           amount=c(100,200,300,400,500,600,700,800,900,
                                    1000,1100,1200,1300,1400,1500,1600,
                                    1700,1800,1900,2000), 
                           ID=c(1,1,2,2,2,3,3,3,5,6,8,9,10,13,15,17,19,20,21,7))


  merge_data_2
   year amount ID
1  1999    100  1
2  1999    200  1
3  2000    300  2
4  2000    400  2
5  2000    500  2
6  2001    600  3
7  2003    700  3
8  2012    800  3
9  2009    900  5
10 2009   1000  6
11 2008   1100  8
12 2002   1200  9
13 2009   1300 10
14 2005   1400 13
15 2001   1500 15
16 2000   1600 17
17 2002   1700 19
18 2000   1800 20
19 2008   1900 21
20 2005   2000  7

而我想要的是:

 ID position school year1 year2 amount
 1    yes    a      2000  1999  300
 2    no     b      2000  1999  1200
10    yes    e      2009  2008  1300

对于merge_data_2中的ID=1，我们有amount=300，因为有2种情况ID=1，并且他们的year1或year1等于merge_data中ID=1的年份

所以基本上我想要的是根据 ID 和年份执行合并。
2条件:

merge_data 中的 ID 与 merge_data_2 中的 ID 匹配

merge_data 中的 year1 和 year2 之一也与 merge_data_2 中的年份匹配。
然后根据每个 ID 的金额总和进行合并。

我认为代码将如下所示:

merge_data_final <- merge(merge_data, merge_data_2, 
                          merge_data$ID == merge_data_2$ID && (merge_data$year1 || 
                            merge_data$year2 == merge_data_2$year))

Then somehow to aggregate the amount by ID.

显然我知道代码是错误的，并且我一直在考虑 plyr 或 reshape 库，但是很难掌握它们。

任何帮助都会很棒!谢谢你们!

Answer 1

如上所述，我认为您的示例输入和输出数据之间存在一些差异。这是基本方法 - 您使用 reshape2 走在正确的轨道上.您可以简单地melt()您的数据转换为长格式，因此您将加入单个列，而不是您之前进行的任一/或位。

library(reshape2)
#melt into long format
merge_data_m <- melt(merge_data, measure.vars = c("year1", "year2"))
#merge together, specifying the joining columns
merge(merge_data_m, merge_data_2, by.x = c("ID", "value"), by.y = c("ID", "year"))
#-----
  ID value position school variable amount
1  1  1999      yes      a    year2    100
2  1  1999      yes      a    year2    200
3  2  2000       no      b    year1    500
4  2  2000       no      b    year1    300
5  2  2000       no      b    year1    400