英文:
R + dplyr: Partial Deduplication of Rows in a Tibble
问题
一个非常常见的问题是如何在R中删除数据框中的所有重复行，可以使用各种工具来完成（我喜欢dplyr+distinct）。
然而，如果您的数据集包含多个重复的行，但您不想删除所有重复行，只想删除某些变量的组合，该怎么办呢？
我不知道如何实现这一点，所以欢迎任何建议。
请查看帖子末尾的reprex。
感谢！
library(dplyr)#>#> Attaching package: 'dplyr'#> The following objects are masked from 'package:stats':#>#> filter, lag#> The following objects are masked from 'package:base':#>#> intersect, setdiff, setequal, uniondf <- tibble(x=rep(seq(5), 3), y=rep(LETTERS[1:5],3),z=c(rep(c("h","j","k","t","u"), 2), LETTERS[1:5]))df#> # A tibble: 15 × 3#> x y z#> <int> <chr> <chr>#> 1 1 A h#> 2 2 B j#> 3 3 C k#> 4 4 D t#> 5 5 E u#> 6 1 A h#> 7 2 B j#> 8 3 C k#> 9 4 D t#> 10 5 E u#> 11 1 A A#> 12 2 B B#> 13 3 C C#> 14 4 D D#> 15 5 E Edf_ded <- df |>distinct()df_ded#> # A tibble: 10 × 3#> x y z#> <int> <chr> <chr>#> 1 1 A h#> 2 2 B j#> 3 3 C k#> 4 4 D t#> 5 5 E u#> 6 1 A A#> 7 2 B B#> 8 3 C C#> 9 4 D D#> 10 5 E E## 我只想要去重x==3和z=="k"的行。df_ded_partial <- df |>distinct(x==3, z=="k") ## 但这不是我想要的。## 如何实现呢？df_ded_partial#> # A tibble: 3 × 2#> `x == 3` `z == "k"`#> <lgl> <lgl>#> 1 FALSE FALSE#> 2 TRUE TRUE#> 3 TRUE FALSE
使用reprex v2.0.2于2023年02月14日创建
英文:
A very common question is how to remove all the duplicated lines in a data frame in R, something which can be done with a variety of tools (I like dplyr+distinct).
However, what if your dataset contains several duplicated lines, but you do not want to remove all of them, but only those for some combination of the variables?
I do not know how to achieve that, so any suggestion is welcome.
Please have a look at the reprex at the end of the post.
Thanks!
library(dplyr)#>#> Attaching package: 'dplyr'#> The following objects are masked from 'package:stats':#>#> filter, lag#> The following objects are masked from 'package:base':#>#> intersect, setdiff, setequal, uniondf <- tibble(x=rep(seq(5), 3), y=rep(LETTERS[1:5],3),z=c(rep(c("h","j","k","t","u"), 2), LETTERS[1:5]))df#> # A tibble: 15 × 3#> x y z#> <int> <chr> <chr>#> 1 1 A h#> 2 2 B j#> 3 3 C k#> 4 4 D t#> 5 5 E u#> 6 1 A h#> 7 2 B j#> 8 3 C k#> 9 4 D t#> 10 5 E u#> 11 1 A A#> 12 2 B B#> 13 3 C C#> 14 4 D D#> 15 5 E Edf_ded <- df |>distinct()df_ded#> # A tibble: 10 × 3#> x y z#> <int> <chr> <chr>#> 1 1 A h#> 2 2 B j#> 3 3 C k#> 4 4 D t#> 5 5 E u#> 6 1 A A#> 7 2 B B#> 8 3 C C#> 9 4 D D#> 10 5 E E## I want to deduplicate only the rows with x==3 and z=="k"df_ded_partial <- df |>distinct(x==3, z=="k") ## but this is not what I mean.## How to achieve it?df_ded_partial#> # A tibble: 3 × 2#> `x == 3` `z == "k"`#> <lgl> <lgl>#> 1 FALSE FALSE#> 2 TRUE TRUE#> 3 TRUE FALSE
<sup>Created on 2023-02-14 with reprex v2.0.2</sup>
答案1
得分: 5
我们可以使用 group_modify() 并使用 .y 参数来检查条件，该参数是当前分组的 tibble。所以我们可以说：如果条件满足，则返回 distinct(.x) 分组，否则返回整个分组 .x。
library(dplyr)df |>group_by(x, z) |>group_modify(~ if(.y$x == 3 && .y$z == "k") distinct(.x) else .x)#> # A tibble: 14 x 3#> # Groups: x, z [10]#> x z y#> <int> <chr> <chr>#> 1 1 A A#> 2 1 h A#> 3 1 h A#> 4 2 B B#> 5 2 j B#> 6 2 j B#> 7 3 C C#> 8 3 k C#> 9 4 D D#> 10 4 t D#> 11 4 t D#> 12 5 E E#> 13 5 u E#> 14 5 u E
来自 OP 的数据
df <- tibble(x=rep(seq(5), 3), y=rep(LETTERS[1:5],3),z=c(rep(c("h","j","k","t","u"), 2), LETTERS[1:5]))
创建于 2023-02-14，由 reprex package (v2.0.1) 创建
英文:
We can use group_modify() and check for the condition using the .y argument which is a tibble of the current group. So we can say: if the condition is met return the distinct(.x) group otherwise return the whole group .x.
library(dplyr)df |>group_by(x, z) |>group_modify(~ if(.y$x == 3 && .y$z == "k") distinct(.x) else .x)#> # A tibble: 14 x 3#> # Groups: x, z [10]#> x z y#> <int> <chr> <chr>#> 1 1 A A#> 2 1 h A#> 3 1 h A#> 4 2 B B#> 5 2 j B#> 6 2 j B#> 7 3 C C#> 8 3 k C#> 9 4 D D#> 10 4 t D#> 11 4 t D#> 12 5 E E#> 13 5 u E#> 14 5 u E
Data from OP
df <- tibble(x=rep(seq(5), 3), y=rep(LETTERS[1:5],3),z=c(rep(c("h","j","k","t","u"), 2), LETTERS[1:5]))
<sup>Created on 2023-02-14 by the reprex package (v2.0.1)</sup>
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