用 NAs 按时间和变量 ID 合并两个数据帧

Merge two dataframes by time and variable ID with NAs

我目前正在使用 R 中的一些货币并希望合并或覆盖两个数据集以创建一个。

对于所有货币,我在 DF1 中有 1980 年到 2017 年的数据。对于其中的 16 个,我还拥有从 1970 年到 1975 年到 2017 年不同地点的数据 DF2。我想要做的是将 DF2 中的 1970-1980 部分放在 DF1 之上。我想如果我设法将 DF1 合并到 DF2 中,它们都有值(因此 DF1 覆盖 DF2),我想我会得到相同的结果。但是,并非所有货币的开始日期都完全相同,所以我不能硬编码。

下面是一个向您展示其外观的示例: Date为时间变量(月度数据)。 DF1 对应 1980-2017 年的数据,DF2 对应 1970-2017 年的数据。我的 objective 是根据列 ID 和行 ID 将 DF1 中的值覆盖到 DF2 中。 DF3 是所需的输出,没有来自 DF1 的 NA,只有来自 DF2 的值。

set.seed(1234)
DF1=data.frame(matrix(data=c(c(4:9),rnorm(30)),6,6))
set.seed(4321)
DF2=data.frame(matrix(data=c(c(1:12),rnorm(36)),12,4))
names(DF1)=c("Date","Currency1","Currency3","Currency6","Currency7","Currency8")
names(DF2)=c("Date","Currency1","Currency2","Currency3")
DF1$Currency3[1:2]=NA
DF1$Currency1[4:5]=NA

> DF1
  Date  Currency1  Currency3   Currency6  Currency7  Currency8
1    4 -1.2070657         NA -0.77625389 -0.8371717 -0.6937202
2    5  0.2774292         NA  0.06445882  2.4158352 -1.4482049
3    6  1.0844412 -0.5644520  0.95949406  0.1340882  0.5747557
4    7         NA -0.8900378 -0.11028549 -0.4906859 -1.0236557
5    8         NA -0.4771927 -0.51100951 -0.4405479 -0.0151383
6    9  0.5060559 -0.9983864 -0.91119542  0.4595894 -0.9359486

> DF2
   Date   Currency1    Currency2   Currency3
1     1 -0.42675738 -1.260985237 -0.09920208
2     2 -0.22361182  1.139464085 -0.23803425
3     3  0.71760679 -1.221781923  0.04778266
4     4  0.84144567  1.573315888  0.29651274
5     5 -0.12835727  0.073477874 -0.83380992
6     6  1.60934721 -1.175115087 -1.37397000
7     7 -0.29716745 -1.588261899  0.14027895
8     8  0.19600465 -0.747380729  0.66212596
9     9  1.24074620  0.483521864  1.13103967
10   10 -0.71869815 -0.003025539 -0.47511202
11   11 -0.06723632 -0.008930402  0.85241411
12   12  0.34436710  0.593357619 -0.75151885

我从一个用户那里得到了这个答案,但我遇到了一个新问题,DF1 中的一些数据中有 NAs,这段代码将其覆盖到 DF2 .

library(data.table)
DF3 <- copy(DF2)
nm1 <- names(DF1)[-1]
setDT(DF3)[DF1, (nm1) := mget(paste0("i.", nm1)), on = .(Date)]

    > DF3
    Date  Currency1  Currency2    Currency3   Currency6  Currency7  Currency8
 1:    1  1.1022975 -0.8553646 -0.162309524          NA         NA         NA
 2:    2 -0.4755931 -0.2806230  0.563055819          NA         NA         NA
 3:    3 -0.7094400 -0.9943401  1.647817473          NA         NA         NA
 4:    4 -1.2070657 -0.9685143           NA -0.77625389 -0.8371717 -0.6937202
 5:    5  0.2774292 -1.1073182           NA  0.06445882  2.4158352 -1.4482049
 6:    6  1.0844412 -1.2519859 -0.564451999  0.95949406  0.1340882  0.5747557
 7:    7         NA -0.5238281 -0.890037829 -0.11028549 -0.4906859 -1.0236557
 8:    8         NA -0.4968500 -0.477192700 -0.51100951 -0.4405479 -0.0151383
 9:    9  0.5060559 -1.8060313 -0.998386445 -0.91119542  0.4595894 -0.9359486
10:   10 -0.4658975 -0.5820759 -0.669633580          NA         NA         NA
11:   11  1.4494963 -1.1088896 -0.007604756          NA         NA         NA
12:   12 -1.0686427 -1.0149620  1.777084448          NA         NA         NA

要仅替换 DF3 中在 DF1 中具有非缺失对应值的值,您可以使用 ifelse.

使用:

DF3 <- copy(DF2)
nm1 <- names(DF1)[-1]
nm2 <- names(DF2)
setDT(DF3)[DF1, (nm1) := {n <- seq_along(nm1);
                          lapply(n, function(i) ifelse(is.na(get(paste0("i.", nm1[i]))) & nm1[i] %in% nm2, 
                                                       get(paste0("x.", nm1[i])), 
                                                       get(paste0("i.", nm1[i]))))},
           on = .(Date)]

你得到:

> DF3
    Date   Currency1    Currency2   Currency3   Currency6  Currency7  Currency8
 1:    1 -0.42675738 -1.260985237 -0.09920208          NA         NA         NA
 2:    2 -0.22361182  1.139464085 -0.23803425          NA         NA         NA
 3:    3  0.71760679 -1.221781923  0.04778266          NA         NA         NA
 4:    4 -1.20706575  1.573315888  0.29651274 -0.77625389 -0.8371717 -0.6937202
 5:    5  0.27742924  0.073477874 -0.83380992  0.06445882  2.4158352 -1.4482049
 6:    6  1.08444118 -1.175115087 -0.56445200  0.95949406  0.1340882  0.5747557
 7:    7 -0.29716745 -1.588261899 -0.89003783 -0.11028549 -0.4906859 -1.0236557
 8:    8  0.19600465 -0.747380729 -0.47719270 -0.51100951 -0.4405479 -0.0151383
 9:    9  0.50605589  0.483521864 -0.99838644 -0.91119542         NA -0.9359486
10:   10 -0.71869815 -0.003025539 -0.47511202          NA         NA         NA
11:   11 -0.06723632 -0.008930402  0.85241411          NA         NA         NA
12:   12  0.34436710  0.593357619 -0.75151885          NA         NA         NA

已用数据:

set.seed(1234)
DF1=data.frame(matrix(data=c(c(4:9),rnorm(30)),6,6))
set.seed(4321)
DF2=data.frame(matrix(data=c(c(1:12),rnorm(36)),12,4))
names(DF1)=c("Date","Currency1","Currency3","Currency6","Currency7","Currency8")
names(DF2)=c("Date","Currency1","Currency2","Currency3")
DF1$Currency3[1:2]=NA
DF1$Currency1[4:5]=NA
DF1$Currency7[nrow(DF1)]=NA

1) sqldf 使用 coalesce 执行 DF1DF2 的左连接,以挑选出第一个非缺失的参数:

library(sqldf)
sqldf("select Date,
              coalesce(DF1.Currency1, DF2.Currency1) Currency1,
              DF2.Currency2,
              coalesce(DF1.Currency3, DF2.Currency3) Currency3
       from DF2 left join DF1 using (Date)")

给予:

   Date   Currency1   Currency2  Currency3
1     1  1.12493092 -0.15579551  1.1000254
2     2 -0.04493361 -1.47075238  0.7631757
3     3 -0.01619026 -0.47815006 -0.1645236
4     4 -0.83562860  0.41794156 -0.2533617
5     5  1.59528080  1.35867955  0.6969634
6     6  0.32950780 -0.10278773  1.5117812
7     7 -0.82046840  0.38767161  0.3898432
8     8  0.48742910 -0.05380504 -0.6212406
9     9  0.73832470 -1.37705956 -2.2146999
10   10 -1.98935170 -0.41499456  0.7685329
11   11  0.61982575 -0.39428995 -0.1123462
12   12 -0.05612874 -0.05931340  0.8811077

名称可以这样参数化:

Date <- names(DF2)[1]
Currency1 <- names(DF2)[2]
Currency2 <- names(DF2)[3]
Currency3 <- names(DF2)[4]

fn$sqldf("select [$Date],
              coalesce(DF1.[$Currency1], DF2.[$Currency1]) [$Currency1],
              DF2.[$Currency2],
              coalesce(DF1.[$Currency3], DF2.[$Currency3]) [$Currency3]
       from DF2 left join DF1 using ([$Date])")

只有在任意名称包含特殊字符的情况下才需要方括号。如果已知情况并非如此,则可以省略方括号。

另一种参数化方法是将数据框的列重命名为标准名称,使用标准名称进行计算,然后恢复原始名称。这里 DF1DF2 具有任意列名称,而 DF1xDF2x 具有上面使用的标准名称。这种方法可以更普遍地工作(例如,它也可以与 (2) 中所示的 dplyr 代码一起工作)。

DF1x <- setNames(DF1, c("Date", "Currency1", "Currency2", "Currency3")
DF2x <- setNames(DF2, c("Date", "Currency1", "Currency3"))

s <- sqldf("select Date,
              coalesce(DF1x.Currency1, DF2x.Currency1) Currency1,
              DF2x.Currency2,
              coalesce(DF1x.Currency3, DF2x.Currency3) Currency3
       from DF2x left join DF1x using (Date)")

names(s) <- names(DF2)

2) dplyr dplyr 可以用基本相同的方式来做,甚至有一个 coalesce 函数:

library(dplyr)
DF2 %>% 
     left_join(DF1, by = "Date") %>%
     transmute(Date,
               Currency1 = coalesce(Currency1.y, Currency1.x),
               Currency2,
               Currency3 = coalesce(Currency3.y, Currency3.x))

给予:

   Date   Currency1   Currency2  Currency3
1     1  1.12493092 -0.15579551  1.1000254
2     2 -0.04493361 -1.47075238  0.7631757
3     3 -0.01619026 -0.47815006 -0.1645236
4     4 -0.83562860  0.41794156 -0.2533617
5     5  1.59528080  1.35867955  0.6969634
6     6  0.32950780 -0.10278773  1.5117812
7     7 -0.82046840  0.38767161  0.3898432
8     8  0.48742910 -0.05380504 -0.6212406
9     9  0.73832470 -1.37705956 -2.2146999
10   10 -1.98935170 -0.41499456  0.7685329
11   11  0.61982575 -0.39428995 -0.1123462
12   12 -0.05612874 -0.05931340  0.8811077

注意: 定义问题输入的原始代码没有使用 set.seed 使其不可重现,因此我们使用了以下对应于最初显示的输入在问题中。 (此后问题已修复添加set.seed。)

DF1 <-
structure(list(Date = 4:9, Currency1 = c(-0.8356286, 1.5952808, 
0.3295078, -0.8204684, 0.4874291, 0.7383247), Currency3 = c(NA, 
NA, 1.5117812, 0.3898432, -0.6212406, -2.2146999)), .Names = c("Date", 
"Currency1", "Currency3"), class = "data.frame", row.names = c("1", 
"2", "3", "4", "5", "6"))

DF2 <-
structure(list(Date = 1:12, Currency1 = c(1.12493092, -0.04493361, 
-0.01619026, 0.94383621, 0.8212212, 0.59390132, 0.91897737, 0.7821363, 
0.07456498, -1.9893517, 0.61982575, -0.05612874), Currency2 = c(-0.15579551, 
-1.47075238, -0.47815006, 0.41794156, 1.35867955, -0.10278773, 
0.38767161, -0.05380504, -1.37705956, -0.41499456, -0.39428995, 
-0.0593134), Currency3 = c(1.1000254, 0.7631757, -0.1645236, 
-0.2533617, 0.6969634, 0.5566632, -0.6887557, -0.7074952, 0.364582, 
0.7685329, -0.1123462, 0.8811077)), .Names = c("Date", "Currency1", 
"Currency2", "Currency3"), class = "data.frame", row.names = c("1", 
"2", "3", "4", "5", "6", "7", "8", "9", "10", "11", "12"))