如何只删除连续的重复行？

Question

我需要删除数据框中的所有重复项，只有当它们出现在连续的行中时。我尝试了 distinct() 函数，但它删除了所有重复项 - 所以我需要一个不同的代码，让我有机会自定义并说仅当重复项是连续的并且仅针对特定列时才删除。

这是我的数据示例：

 Subject  Trial Event_type  Code   Time 
    
23  VP02_RP 15  Picture face01_n    887969

24  VP02_RP 15  Sound   mpossound_test5 888260

25  VP02_RP 15  Picture pospic_test5    906623

26  VP02_RP 15  Nothing ev_mnegpos_adj_onset    928623

27  VP02_RP 15  Response    15  958962

28  VP02_RP 18  Picture face01_p    987666

29  VP02_RP 18  Sound   mpossound_test6 987668

30  VP02_RP 18  Picture negpic_test6    1006031

31  VP02_RP 18  Nothing ev_mposnegpos_adj_onset 1028031

32  VP02_RP 18  Response    15  1076642

33  VP02_RP 19  Response    13  1680887

正如您在第 32 和 33 行中看到的，我有两个连续的回复，我只想保留第一个。所以我想删除 Event_type 列中所有重复的连续行。

我该怎么办？

Answer 1

您可以使用 data.table 中的 rleid 函数，它将为每个连续的事件值提供一个唯一的数字，然后使用 duplicated 只保留第一个。

res <- df[!duplicated(data.table::rleid(df$Event_type)), ]
res

#   Subject Trial Event_type                    Code    Time
#23 VP02_RP    15    Picture                face01_n  887969
#24 VP02_RP    15      Sound         mpossound_test5  888260
#25 VP02_RP    15    Picture            pospic_test5  906623
#26 VP02_RP    15    Nothing    ev_mnegpos_adj_onset  928623
#27 VP02_RP    15   Response                      15  958962
#28 VP02_RP    18    Picture                face01_p  987666
#29 VP02_RP    18      Sound         mpossound_test6  987668
#30 VP02_RP    18    Picture            negpic_test6 1006031
#31 VP02_RP    18    Nothing ev_mposnegpos_adj_onset 1028031
#32 VP02_RP    18   Response                      15 1076642

rleid 基数 R 中的函数可以写成 rle -

res <- df[!duplicated(with(rle(df$Event_type),rep(seq_along(values), lengths))),]
res

Answer 2

一个潜在的 tidyverse 解决方案：

library(tidyverse)

df1 <- data.frame(
  stringsAsFactors = FALSE,
         row.names = c("23","24","25","26","27",
                       "28","29","30","31","32","33"),
           Subject = c("VP02_RP","VP02_RP","VP02_RP",
                       "VP02_RP","VP02_RP","VP02_RP","VP02_RP","VP02_RP",
                       "VP02_RP","VP02_RP","VP02_RP"),
             Trial = c(15L, 15L, 15L, 15L, 15L, 18L, 18L, 18L, 18L, 18L, 19L),
        Event_type = c("Picture","Sound","Picture",
                       "Nothing","Response","Picture","Sound","Picture",
                       "Nothing","Response","Response"),
              Code = c("face01_n","mpossound_test5",
                       "pospic_test5","ev_mnegpos_adj_onset","15","face01_p",
                       "mpossound_test6","negpic_test6",
                       "ev_mposnegpos_adj_onset","15","13"),
              Time = c(887969L,888260L,906623L,
                       928623L,958962L,987666L,987668L,1006031L,1028031L,
                       1076642L,1680887L)
)

df1 %>%
  filter(Event_type != lag(Event_type, 1))
#>    Subject Trial Event_type                    Code    Time
#> 24 VP02_RP    15      Sound         mpossound_test5  888260
#> 25 VP02_RP    15    Picture            pospic_test5  906623
#> 26 VP02_RP    15    Nothing    ev_mnegpos_adj_onset  928623
#> 27 VP02_RP    15   Response                      15  958962
#> 28 VP02_RP    18    Picture                face01_p  987666
#> 29 VP02_RP    18      Sound         mpossound_test6  987668
#> 30 VP02_RP    18    Picture            negpic_test6 1006031
#> 31 VP02_RP    18    Nothing ev_mposnegpos_adj_onset 1028031
#> 32 VP02_RP    18   Response                      15 1076642

Answer 3

选项data.table

library(data.table)
setDT(df1)[Event_type != shift(Event_type)]

如何只删除连续的重复行？

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