# How to Make a Scatter Plot Matrix in R

Last Updated : 17 Apr, 2023

A scatterplot matrix is â€‹â€‹a grid of scatterplots that allows us to see how different pairs of variables are related to each other. We can easily generate a scatterplot matrix using the pairs() function in R programming. In this article, we will walk through the process of creating a scatterplot matrix in R step by step using different packages.

Before we start, make sure you have R and R Studio installed on your computer, which contains the following R packages: ggplot2 , GGally, and Psych. If you don’t have these packages installed, you can install them by running the following code in the console of R Studio:

```install.packages("ggplot2")
install.packages("GGally")
install.packages("psych")```

## How to make a Scatterplot Matrix in R using pairs() function?

The pairs() function is a function that is used to create a scatterplot matrix for a given set of variables of a dataset. It is a useful function that helps in examining the relationship between multiple variables in a dataset. It creates a scatterplot matrix with variables plotted against every other variable in the dataset.

Here are some step which help you in creating scatter plot matrix in R using pairs() function:

We need to load the data for which we want to create a scatterplot matrix. The data() function allows us to load data. In this example, we’ll use R built-in dataset mtcars that contains information about 32 different car models. The dataset contains 11 variables, such as miles per gallon (mpg), number of cylinders, horsepower, weight, acceleration, and many more.

`data(mtcars)`

Step 2: Create a scatterplot matrix using the pairs() function

`pairs(mtcars[, c(1, 3:6)], main = "Scatter Plot Matrix for mtcars Dataset")`

Some of the parameters which we can use to our plot more interactive graphs are as follows:

1. diag.panel: This is a parameter of the pairs() function, which is used to create a histogram or density plot for each variable in the diagonal part of the matrix.
2. text.panel: This is a parameter of the pairs() function, which is used to add text to the matrix.
3. scale: This is a parameter of the pairs() function, which is used to adjust the size of the plot.
4. font.labels: This is a parameter of the pairs() function, which specifies the font size of the label.

Complete Code for creating Scatter Plot Matrix using Pairs() Function:

## R

 `data``(mtcars) ` `# Create a scatter plot matrix using the pairs() function ` `pairs``(mtcars[, ``c``(1, 3:6)], main = ``"Scatter Plot Matrix for mtcars Dataset"``)`

Output:

Scatterplot Matrix using pair() function

## How to Make a Scatterplot Matrix in R using GGally Package?

In the GGally package we have a ggpairs() function which we can use to create a matrix of scatterplots for a given set of variables of a dataset to examine pairwise relationships between variables in a dataset. It creates a scatterplot matrix with variables plotted against every other variable in the dataset.

Here are some steps which will help you in creating a scatter plot matrix in R using GGally Package:

Step 1: Importing Required Packages

```library(ggplot2)
library(GGally)```

Next, we need to load the data for which we want to create a scatterplot matrix. In this example, we’ll use R built-in dataset mtcars, which is a dataset of cars, using the data() method.

`data(mtcars)`

Step 3: Create Scatterplot using ggpairs() method

We’ll use the ggpairs() function from the GGally package to make a scatter plot matrix. This function accepts a dataset along with a number of parameters that determine how the plot will look.

```Scatter_Matrix <- ggpairs(mtcars,columns = c(1, 3:6),
title = "Scatter Plot Matrix for mtcars Dataset", axisLabels = "show")```

Some of the parameters which we can use to our plot a more interactive graph are as follows:

1. diag: It is used for the diagonal of the matrix of plots for specific requirements. For example ‘diag=”density”‘: which adds a density plot to the diagonal of each plot.
2. upper: It is used for applying the specific requirements to the upper triangle of the matrix of plots.
3. lower: It is used for applying the specific requirements to the lower triangle of the matrix of plots.

Step 4: Save the Scatterplot (optional)

The ggsave() method can be used to save our scatter plot matrix as an image file once we are satisfied with our scatter plot matrix.

`ggsave("scatter plot matrix.png", Scatter_Matrix, width = 7, height = 7, units = "in")`

The complete Code for creating Scatterplot Matrix Using GGally Package is as follows:

## R

 `library``(ggplot2) ` `library``(GGally) ` `data``(mtcars) ` `Scatter_Matrix <- ``ggpairs``(mtcars,columns = ``c``(1, 3:6), ` `                          ``title = ``"Scatter Plot Matrix for mtcars Dataset"``, ` `                          ``axisLabels = ``"show"``) ` `ggsave``(``"Scatter plot matrix.png"``, Scatter_Matrix, width = 7, ` `       ``height = 7, units = ``"in"``) ` `Scatter_Matrix`

#### Output:

Scatterplot using ggpairs() function

## How to Make a Scatterplot Matrix in R using Psych Package?

In the Psych package, we have a pairs.panel() function which is used to create a matrix of scatterplots for a given set of variables of a dataset to examine pairwise relationships between variables in a dataset. It creates a scatterplot matrix with variables plotted against every other variable in the dataset and it also has correlation coefficients for each pair of variables of a dataset.

Here are some steps that will help you create a scatter plot matrix in R using Psych Package:

Step 1: Importing Required Packages

```library(ggplot2)
library(psych)```

Next, we need to load the data for which we want to create a scatterplot matrix.

`data(mtcars)`

Step 3: Create Scatterplot using pairs.panels() function

We’ll use the pairs.panels() function from the psych package to make a scatter plot matrix. This function accepts a dataset along with a number of parameters that determine how the plot will look.

`Scatter_Matrix <- pairs.panels(mtcars[, c(1, 3:6)], main = "Scatter Plot Matrix for mtcars Dataset")`

Some of the parameters which we can use to our plot more interactive:

1. col: It is used for specifying the color of the points in the plot.
2. bg: It is used for specifying the background color of the plot.
3. pch: It is used for specifying the type of symbol to be used in the plot.
4. labels: It is used for specifying the labels for the variables in a given dataset.

Step 4: Save the Scatterplot (optional)

(optional)The ggsave() method can be used to save our scatter plot matrix as an image file once we are satisfied with our scatter plot matrix.

`ggsave("scatter plot matrix.png", Scatter_Matrix, width = 7, height = 7, units = "in")`

Complete Code for creating Scatter Plot Matrix using Psych Package

## R

 `library``(ggplot2) ` `library``(psych) ` `data``(mtcars) ` `Scatter_Matrix <- ``pairs.panels``(mtcars[, ``c``(1, 3:6)], main = ``"Scatter Plot Matrix for mtcars Dataset"``) ` `ggsave``(``"scatter plot matrix.png"``, Scatter_Matrix, width = 7, height = 7, units = ``"in"``) `

#### Output:

Scatterplot using Psych Package