如何在 R 的模式中反转 dataframe 的顺序

Question

我想以特定顺序反转以下数据帧。

Stage       Score 
W-3         25
W-3         2 Min 10 Sec
W-2         45
W-2         1 Min 34 Sec
W-1         75
W-1         1 Min 04 Sec

我想按以下顺序反转它。

Stage       Score
W-1         75
W-1         1 Min 04 Sec
W-2         45
W-2         1 Min 34 Sec
W-3         25
W-3         2 Min 10 Sec

我正在使用df<- df[seq(dim(df)[1],1),]但它没有用。

Answer 1

我们可以使用具有以“阶段”的unique元素的rev顺序指定的levels的factor

library(dplyr)
df2 <- df1 %>%
    arrange(factor(as.character(Stage), 
             levels = rev(unique(as.character(Stage)))))

与“日期”列相同

df1 %>%
    arrange(factor(as.character(Date), 
             levels = rev(unique(as.character(Date)))))

-输出

# Stage        Score       Date
#1   W-1 1 Min 04 Sec 2020-12-15
#2   W-1           75 2020-12-14
#3   W-2 1 Min 34 Sec 2020-12-13
#4   W-2           45 2020-12-12
#5   W-3 2 Min 10 Sec 2020-12-11
#6   W-3           25 2020-12-10

---

或使用base R

df2 <- df1[order(factor(df1$Stage, levels = rev(unique(df1$Stage)))),]

数据

df1 <- structure(list(Stage = c("W-3", "W-3", "W-2", "W-2", "W-1", "W-1"
), Score = c("25", "2 Min 10 Sec", "45", "1 Min 34 Sec", "75", 
"1 Min 04 Sec"), Date = structure(18606:18611, class = "Date")),
row.names = c(NA, 
-6L), class = "data.frame")

Answer 2

使用order + ave的另一个基本 R 选项

df[with(df, order(Stage, ave(1:nrow(df), Stage, FUN = seq_along))), ]

这使

  Stage        Score
5   W-1           75
6   W-1 1 Min 04 Sec
3   W-2           45
4   W-2 1 Min 34 Sec
1   W-3           25
2   W-3 2 Min 10 Sec

数据

> dput(df)
structure(list(Stage = c("W-3", "W-3", "W-2", "W-2", "W-1", "W-1"
), Score = c("25", "2 Min 10 Sec", "45", "1 Min 34 Sec", "75",
"1 Min 04 Sec")), row.names = c(NA, -6L), class = "data.frame")

Answer 3

我们还可以使用mixedorder中的gtools 。

df <- data.frame("Stage" = c('W-3', 'W-3', 'W-2',
                             'W-2', 'W-1', 'W-1'),
                 "Score" = c(25, '2 Min 10 Sec', 45,
                             '1 Min 34 Sec', 75, '1 Min 04 Sec' ))

library(gtools)
df[mixedorder(df$Stage, decreasing = T), ]

---

  Stage        Score
5   W-1           75
6   W-1 1 Min 04 Sec
3   W-2           45
4   W-2 1 Min 34 Sec
1   W-3           25
2   W-3 2 Min 10 Sec