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Sorting a data frame by date in R is a common task that involves arranging the rows of a data frame in chronological order based on a specific date column. This can be achieved using the “order()” function, which takes in the date column as an argument and returns the index of the rows in the desired order. Alternatively, the “arrange()” function from the “dplyr” package can also be used to sort a data frame by date, providing more flexibility in specifying the sorting criteria. For example, if we have a data frame with a “Date” column, we can use the “order()” function to sort the data frame by date as follows:
order(df$Date)
This will return the index of the rows in ascending order based on the values in the “Date” column. Similarly, using the “arrange()” function, we can sort the data frame by date in descending order as follows:
arrange(df, desc(Date))
This will arrange the rows of the data frame in descending order based on the “Date” column. Overall, sorting a data frame by date in R is a simple yet essential task, and with the help of the “order()” and “arrange()” functions, it can be easily accomplished.
Sort a Data Frame by Date in R (With Examples)
There are two easy ways to sort a data frame by date in R:
Method 1: User order() from base R
#sort from least recent to most recent df[order(as.Date(df$date, format="%m/%d/%Y")),] #sort from most recent to least recent df[rev(order(as.Date(df$date, format="%m/%d/%Y"))),]
Method 2: Use functions from the lubridate and dplyr packages
library(lubridate)library(dplyr)#sort from least recent to most recent df %>% arrange(mdy(df$date)) #sort from most recent to least recent df %>% arrange(desc(mdy(df$date)))
This tutorial shows an example of how to use each of these methods in practice.
Method 1: Use order() from base R
The most basic way to sort a data frame by a date variable in R is to use the order() function from base R. The following code shows how to use this function in practice:
#create and view data frame df <- data.frame(date=c('10/30/2021', '11/18/2021', '11/13/2021', '11/19/2021'), sales=c(3, 15, 14, 9)) df date sales 1 10/30/2021 3 2 11/18/2021 15 3 11/13/2021 14 4 11/19/2021 9 #sort from least recent to most recent df[order(as.Date(df$date, format="%m/%d/%Y")),] date sales 1 10/30/2021 3 3 11/13/2021 14 2 11/18/2021 15 4 11/19/2021 9 #sort from most recent to least recent df[rev(order(as.Date(df$date, format="%m/%d/%Y"))),] date sales 4 11/19/2021 9 2 11/18/2021 15 3 11/13/2021 14 1 10/30/2021 3
Method 2: Use lubridate and dplyr
A faster way to sort a data frame by a date variable is to use functions from the lubridate and dplyr packages. The following code shows how to use these functions in practice:
#create and view data frame df <- data.frame(date=c('10/30/2021', '11/18/2021', '11/13/2021', '11/19/2021'), sales=c(3, 15, 14, 9)) df date sales 1 10/30/2021 3 2 11/18/2021 15 3 11/13/2021 14 4 11/19/2021 9#sort from least recent to most recent df %>% arrange(mdy(df$date)) date sales 1 10/30/2021 3 2 11/13/2021 14 3 11/18/2021 15 4 11/19/2021 9 #sort from most recent to least recent df %>% arrange(desc(mdy(df$date))) date sales 1 11/19/2021 9 2 11/18/2021 15 3 11/13/2021 14 4 10/30/2021 3
Note that we used lubridate to specify the date as a mdy() format, but you can refer to this cheat sheet to see other date formats if your date happens to be in a different format.
Additional Resources
How to Extract Year from Date in R
How to Aggregate Daily Data to Monthly and Yearly in R
How to Arrange Rows in R