Table of Contents
The process of extracting the last row in a data frame in R involves retrieving the last row of data from a data frame. This can be achieved by using the function “nrow” to determine the total number of rows in the data frame, and then using the indexing operator “[ ]” to specify the last row. The extracted row can then be assigned to a new data frame or used for further analysis. This method allows for efficient retrieval of the last row of data in R data frames.
Extract Last Row in Data Frame in R
You can use the following methods to extract the last row in a data frame in R:
Method 1: Use Base R
last_row <- tail(df, n=1)
Method 2: Use dplyr
library(dplyr)
last_row <- df %>% slice(n())
Method 3: Use data.table
library(data.table)
last_row <- setDT(df[nrow(df), ])
The following examples show how to use each method with the following data frame in R:
#create data frame df <- data.frame(team=c('A', 'B', 'C', 'D', 'E'), points=c(99, 90, 86, 88, 95), assists=c(33, 28, 31, 39, 34), rebounds=c(30, 28, 24, 24, 28)) #view data frame df team points assists rebounds 1 A 99 33 30 2 B 90 28 28 3 C 86 31 24 4 D 88 39 24 5 E 95 34 28
Example 1: Extract Last Row Using Base R
The following code shows how to extract the last row of the data frame by using the tail() function from base R:
#extract last row in data frame last_row <- tail(df, n=1) #view last row last_row team points assists rebounds 5 E 95 34 28
Using the tail() function, we’re able to extract only the last row in the data frame.
Note that you can change the value for the n argument to instead select the last n rows of the data frame.
Example 2: Extract Last Row Using dplyr
The following code shows how to extract the last row of the data frame by using the slice() function from the dplyr package:
library(dplyr) #extract last row in data frame last_row <- df %>% slice(n()) #view last row last_row team points assists rebounds 1 E 95 34 28
Related:
Example 3: Extract Last Row Using data.table
The following code shows how to extract the last row of the data frame by using functions from the data.table package:
library(data.table) #extract last row in data frame last_row <- setDT(df[nrow(df), ]) #view last row last_row team points assists rebounds 1: E 95 34 28
Using the nrow() function, we’re able to extract only the last row in the data frame.
Cite this article
stats writer (2024). How do you extract the last row in a data frame in R?. PSYCHOLOGICAL SCALES. Retrieved from https://scales.arabpsychology.com/stats/how-do-you-extract-the-last-row-in-a-data-frame-in-r/
stats writer. "How do you extract the last row in a data frame in R?." PSYCHOLOGICAL SCALES, 26 Jun. 2024, https://scales.arabpsychology.com/stats/how-do-you-extract-the-last-row-in-a-data-frame-in-r/.
stats writer. "How do you extract the last row in a data frame in R?." PSYCHOLOGICAL SCALES, 2024. https://scales.arabpsychology.com/stats/how-do-you-extract-the-last-row-in-a-data-frame-in-r/.
stats writer (2024) 'How do you extract the last row in a data frame in R?', PSYCHOLOGICAL SCALES. Available at: https://scales.arabpsychology.com/stats/how-do-you-extract-the-last-row-in-a-data-frame-in-r/.
[1] stats writer, "How do you extract the last row in a data frame in R?," PSYCHOLOGICAL SCALES, vol. X, no. Y, ص Z-Z, June, 2024.
stats writer. How do you extract the last row in a data frame in R?. PSYCHOLOGICAL SCALES. 2024;vol(issue):pages.
