*76*

A **scatterplot** is a type of plot that we can use to display the relationship between two variables. It helps us visualize both the direction (positive or negative) and the strength (weak, moderate, strong) of the relationship between the two variables.

This tutorial explains how to create and modify scatterplots in Stata.

**How to Create Scatterplots in Stata**

We’ll use a dataset called *auto *to illustrate how to create and modify scatterplots in Stata.

First, load the data by typing the following into the Command box:

use http://www.stata-press.com/data/r13/auto

We can get a quick look at the dataset by typing the following into the Command box:

summarize

We can see that there are 12 total variables in the dataset.

**Basic Scatterplot**

We can create a scatterplot for the variables *weight *and *length *by using the **scatter **command. The first variable you type will go along the y-axis and the second variable will go along the x-axis:

scatter weight length

We can see that there is a strong positive correlation between weight and length. That is, cars that weigh more also tend to be longer.

**Scatterplot with a Regression Line**

You can add a simple linear regression line to the scatterplot by using two “pipe” symbols || along with the **lfit **command:

scatter weight length || lfit weight length

**Scatterplot with Multiple Variables**

You can create a scatterplot with more than two variables by simply typing more variables after the **scatter **command. Note that the last variable you type will be used for the x-axis.

For example, the following command tells Stata to create a scatterplot using *length *as the x-axis variable and *weight *and *displacement *as the y-axis variables:

scatter weight displacement length

**How to Modify Scatterplots in Stata**

We can use several different commands to modify the appearance of the scatterplots.

**Adding a Title**

We can add a title to the plot using the **title() **command:

scatter weight length, title(“Weight vs. Length”)

**Adding a Subtitle**

We can also add a subtitle underneath the title using the **subtitle() **command:

scatter weight length, title(“Weight vs. Length”) subtitle(“n = 74 cars”)

**Adding a Comment**

We can also add a note or comment at the bottom of the graph by using the **note() **command:

scatter weight length, note(“Source: 1978 Automobile Data”)

**Changing Colors**

We can change the color of the points in the scatterplot by using the **mcolor() **command:

scatter weight length, mcolor(green)

A full list of available colors can be found in the Stata Documentation for colors.

**Changing Shapes**

We can also change the shape of the points in the scatterplot by using the **msymbol() **command. For example the symbol “D” corresponds to diamonds:

scatter weight length, msymbol(D)

A full list of available shapes can be found in the Stata Documentation for shapes.