How To Generate Random Numbers in R

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DataDaft

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53,300

Published on January 24, 2020 8:10:09 PM ● Video Link: https://www.youtube.com/watch?v=8UyfDajCt4U

Category:

Guide

Duration: 3:52

12,226 views

176

This video shows how to reverse vectors, strings and data frames by both columns and rows in R.

Code used in this clip:

# Initialize random number generator
set.seed(12)

# Generate data uniformly within a given range
runif(100, min = 0, max = 10)


# Generate normally distributed data
random_normal ＜- rnorm(10000, mean = 10, sd = 1)

plot(density(random_normal))


# Generate data by sampling from a vector
die ＜- c(1,2,3,4,5,6)

# Simulate rolling tow dice and adding the result
two_dice ＜- sample(die, size = 10000, replace = TRUE) +
sample(die, size = 10000, replace = TRUE)

table(two_dice)


# Sample rows from a data frame

data ＜- mtcars

index ＜- sample(1:nrow(data),
size = 10,
replace = FALSE)

data[index,]

Code Clips are basic code explanations in 3 minutes or less. They are intended to be short reference guides that provide quick breakdowns and copy/paste access to code needed to accomplish common data science tasks. Think Stack Overflow with a video explanation.


* Note: YouTube does not allow greater than or less than symbols in the text description, so the code above will not be exactly the same as the code shown in the video! For R that means I may use = for assignment and the special Unicode large ＜ and ＞ symbols in place of the standard sized ones for dplyr pipes and comparisons. These special symbols should work as expected for R code on Windows, but may need to be replaced with standard greater than and less than symbols for other operating systems.