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Using the dplyr package, you can round values in specific columns by using the round() function. This is done by specifying the column to be rounded and the number of decimal places you would like to round the values to. For example, you can use the code “df %>% mutate(column_name = round(column_name, 2))” to round the values in the specified column to two decimal places.
You can use the following methods to round values in specific columns of a data frame using the dplyr package in R:
Method 1: Round Values in Specific Columns
library(dplyr) #round values in 'sales' and 'returns' columns to 2 decimal places df_new <- df %>% mutate(across(c('sales', 'returns'), round, 2))
Method 2: Round Values in All Numeric Columns
library(dplyr) #round values in all numeric columns to 2 decimal places df_new <- df %>% mutate(across(where(is.numeric), round, 2))
The following examples show how to use each method in practice with the following data frame in R:
#create data frame df <- data.frame(store=c('A', 'A', 'A', 'B', 'B', 'C', 'C', 'C'), sales=c(4.352, 6.5543, 7.5423, 9.22111, 4.332, 9.55, 8.0094, 7.2), returns=c(1.2324, 2.6654, 3.442, 6.545, 8.11, 8.004, 7.545, 6.0), promos=c(12.11, 14.455, 10.277, 23.51, 20.099, 29.343, 30.1, 45.6)) #view data frame df store sales returns promos 1 A 4.35200 1.2324 12.110 2 A 6.55430 2.6654 14.455 3 A 7.54230 3.4420 10.277 4 B 9.22111 6.5450 23.510 5 B 4.33200 8.1100 20.099 6 C 9.55000 8.0040 29.343 7 C 8.00940 7.5450 30.100 8 C 7.20000 6.0000 45.600
Example 1: Round Values in Specific Columns Using dplyr
The following code shows how to round the values in the sales and returns columns to 2 decimal places:
library(dplyr) #round values in 'sales' and 'returns' columns to 2 decimal places df_new <- df %>% mutate(across(c('sales', 'returns'), round, 2)) #view updated data frame df_new store sales returns promos 1 A 4.35 1.23 12.110 2 A 6.55 2.67 14.455 3 A 7.54 3.44 10.277 4 B 9.22 6.54 23.510 5 B 4.33 8.11 20.099 6 C 9.55 8.00 29.343 7 C 8.01 7.54 30.100 8 C 7.20 6.00 45.600
Notice that the values in the sales and returns columns are rounded to 2 decimal places while all other columns have remain unchanged.
Example 2: Round Values in All Numeric Columns Using dplyr
The following code shows how to round the values in all of the numeric columns to 2 decimal places:
library(dplyr) #round values in all numeric columns 2 decimal places df_new <- df %>% mutate(across(where(is.numeric), round, 2)) #view updated data frame df_new store sales returns promos 1 A 4.35 1.23 12.11 2 A 6.55 2.67 14.46 3 A 7.54 3.44 10.28 4 B 9.22 6.54 23.51 5 B 4.33 8.11 20.10 6 C 9.55 8.00 29.34 7 C 8.01 7.54 30.10 8 C 7.20 6.00 45.60
Notice that the values in all three numeric columns of the data frame have been rounded to 2 decimal places.
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