合并两个数据帧而不重复度量值

Question

我有两个数据框，我想按领导值合并它们，这样我就可以看到每个组的总跑步和步行。每个领导者的团队中可以有多个成员，但我遇到的问题是，当我合并他们时，指标也会复制到新添加的行中。

这是我拥有的两个数据集的示例：

数据集 1：

+-------------+-----------+------------+-------------+
| leader name | leader id | total runs | total walks |
+-------------+-----------+------------+-------------+
| ab          |        11 |          4 |           9 |
| tg          |        47 |          8 |           3 |
+-------------+-----------+------------+-------------+

数据集 2：

+-------------+-----------+--------------+-----------+
| leader name | leader id | member name  | member id |
+-------------+-----------+--------------+-----------+
| ab          |        11 | gfh          |       589 |
| ab          |        11 | tyu          |       739 |
| tg          |        47 | rtf          |       745 |
| tg          |        47 | jke          |       996 |
+-------------+-----------+--------------+-----------+

我想把两个数据集合并成这样：

+-------------+-----------+--------------+------------+------------+-------------+
| leader name | leader id | member name  | member id  | total runs | total walks |
+-------------+-----------+--------------+------------+------------+-------------+
| ab          |        11 | gfh          |        589 |          4 |           9 |
| ab          |        11 | tyu          |        739 |            |             |
| tg          |        47 | rtf          |        745 |          8 |           3 |
| tg          |        47 | jke          |        996 |            |             |
+-------------+-----------+--------------+------------+------------+-------------+

但现在我不断得到：

+-------------+-----------+--------------+------------+------------+-------------+
| leader name | leader id | member name  | member id  | total runs | total walks |
+-------------+-----------+--------------+------------+------------+-------------+
| ab          |        11 | gfh          |        589 |          4 |           9 |
| ab          |        11 | tyu          |        739 |          4 |           9 |
| tg          |        47 | rtf          |        745 |          8 |           3 |
| tg          |        47 | jke          |        996 |          8 |           3 |
+-------------+-----------+--------------+------------+------------+-------------+

只要值不重复，它们是空白、NA 还是 0 都没有关系。有没有办法做到这一点？

Answer 1

我们可以在 left_join 之后的那些“总计”列上执行replace

library(dplyr)
left_join(df2, df1 ) %>%
      group_by(leadername) %>%
      mutate_at(vars(starts_with('total')), ~ replace(., row_number() > 1, NA))
# A tibble: 4 x 6
# Groups:   leadername [2]
#  leadername leaderid membername memberid totalruns totalwalks
#  <chr>         <dbl> <chr>         <dbl>     <dbl>      <dbl>
#1 ab               11 gfh             589         4          9
#2 ab               11 tyu             739        NA         NA
#3 tg               47 rtf             745         8          3
#4 tg               47 jke             996        NA         NA

---

或者不使用group_by

left_join(df2, df1 ) %>%
     mutate_at(vars(starts_with('total')), ~ 
         replace(., duplicated(leadername), NA))

---

或者base R 选项是

out <- merge(df2, df1, all.x = TRUE)
i1 <- duplicated(out$leadername)
out[i1, c("totalruns", "totalwalks")] <- NA
out
#  leadername leaderid membername memberid totalruns totalwalks
#1         ab       11        gfh      589         4          9
#2         ab       11        tyu      739        NA         NA
#3         tg       47        rtf      745         8          3
#4         tg       47        jke      996        NA         NA

数据

df1 <- structure(list(leadername = c("ab", "tg"), leaderid = c(11, 47
), totalruns = c(4, 8), totalwalks = c(9, 3)), class = "data.frame", row.names = c(NA, 
-2L))

df2 <- structure(list(leadername = c("ab", "ab", "tg", "tg"), leaderid = c(11, 
11, 47, 47), membername = c("gfh", "tyu", "rtf", "jke"), memberid = c(589, 
739, 745, 996)), class = "data.frame", row.names = c(NA, -4L))