How to reverse the order of dataframe in a pattern in R

user_13199674 0
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I want to reverse the following data frame in particular sequence.

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

I want to reverse it in following order.

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

I'm using df<- df[seq(dim(df)[1],1),] but it didn't work.

data.table dplyr dataframe r
3 Answers

We can use factor with levels specified in the reverse order of unique elements of 'Stage'

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

And the same with 'Date' column

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

-output

# 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

Or using base R

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

data

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")
user_37322710

Another base R option using order + ave

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

which gives

  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

Data

> 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")
user_121587570

We can also use mixedorder from 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
user_40899490
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