Normal Probability Plot in R

The normal probability plot is the graphical representation of data. This tutorial demonstrates how to plot the normal probability in R.

Normal Probability Plot in R

The normal probability plot shows the normal distribution of the given data set. It compares the dataset with the normal distribution.

It should show a straight line if the data is normally distributed. We can use the ggplot2 with the ggplotr package to plot the normal probability graph.

First of all, install these packages:

install.packages("ggplot2")

install.packages("qqplotr")

Once the packages are successfully installed, we create a data set for normal distribution, for which we will plot the normal probability graph. We will use the functions stat_qq_point() and stat_qq_line() to plot the normal probability.

See example:

install.packages("ggplot2")
install.packages("qqplotr")

library(ggplot2)
library(qqplotr)

# random data for normal distribution
normal_distribution = rnorm(1000, mean = 110, sd = 60)

# plot the data without line and labels
ggplot(mapping = aes(sample = normal_distribution)) + stat_qq_point(size = 3)+ stat_qq_line(color="green")

The code above will plot the graph for the normal probability of given data with a green straight line. See output: