Take Random Samples from a Data Frame in R Programming – sample_n() Function

sample_n() function in R Language is used to take random sample specimens from a data frame.

Syntax: sample_n(x, n)

Parameters:
x: Data Frame
n: size/number of items to select

Example 1:

# R program to collect sample data
# from a data frame

# Loading library
library(dplyr)

# Create a data frame
d <- data.frame( name = c("Abhi", "Bhavesh", "Chaman", "Dimri"),
                 age = c(7, 5, 9, 16),
                 ht = c(46, NA, NA, 69),
                 school = c("yes", "yes", "no", "no") )

# Printing three rows
sample_n(d, 3)

Output:

     name age ht school
1  Chaman   9 NA     no
2    Abhi   7 46    yes
3 Bhavesh   5 NA    yes

Example 2:

# R program to collect sample data
# from a data frame

# Loading library
library(dplyr)

# Create a data frame
d <- data.frame( name = c("Abhi", "Bhavesh", "Chaman", "Dimri"),
                 age = c(7, 5, 9, 16),
                 ht = c(46, NA, NA, 69),
                 school = c("yes", "yes", "no", "no") )

# Printing three rows
sample_n(d, 3, fac = "name")$name

Output:

[1] Chaman  Bhavesh Dimri  
Levels: Abhi Bhavesh Chaman Dimri

Here, in the above code, column name is specified. Hence, the size is applied within the factor.