# theme_test ggplot2 Theme in R (6 Examples)

This article demonstrates how to set the ggplot2 theme to the theme_test in R programming.

You’re here for the answer, so let’s get straight to the examples…

## Example Data & Packages

The following data will be used as basement for this tutorial:

```set.seed(122665) # Set random seed data <- data.frame(x = rnorm(160), # Create example data frame y = rnorm(160), group = LETTERS[1:4]) head(data) # Print head of example data frame``` Table 1 shows that our example data consists of three columns.

In this tutorial, we’ll also need to install and load the ggplot2 package:

```install.packages("ggplot2") # Install & load ggplot2 package library("ggplot2")```

## Example 1: Draw ggplot2 Scatterplot Using theme_test()

```ggplot(data, # theme_test scatterplot aes(x = x, y = y, col = group)) + geom_point() + theme_test()``` ## Example 2: Draw ggplot2 Density Plot Using theme_test()

```ggplot(data, # theme_test density plot aes(x = x, fill = group)) + geom_density(alpha = 0.5) + theme_test()``` ## Example 3: Draw ggplot2 Histogram Using theme_test()

```ggplot(data, # theme_test histogram aes(x = x, fill = group)) + geom_histogram(alpha = 0.5, position = "identity", bins = 50) + theme_test()``` ## Example 4: Draw ggplot2 Barchart Using theme_test()

```ggplot(aggregate(y ~ group, data, sum), # theme_test barplot aes(x = group, y = y, fill = group)) + geom_bar(stat = "identity") + theme_test()``` ## Example 5: Draw ggplot2 Boxplot Using theme_test()

```ggplot(data, # theme_test boxplot aes(x = x, fill = group)) + geom_boxplot() + theme_test()``` ## Example 6: Draw ggplot2 Line Plot Using theme_test()

```ggplot(data, # theme_test line plot aes(x = x, y = y, col = group)) + geom_line() + theme_test()``` ## Video & Further Resources

Would you like to know more about the application of the theme_test ggplot2 theme? Then I can recommend watching the following video on my YouTube channel. In the video, I illustrate the R programming code of this article.

You can also find tutorials on how to plot different types of graphics such as xy-plots, density plots, bargraphs, boxplots, histograms, and line charts using other ggplot2 themes:

Also, you may check out the introductions to other add-on packages that provide extra themes for ggplot2 plots:

In addition, you may want to read some of the related articles on this website. You can find a selection of tutorials below.

To summarize: You have learned on this page how to apply the theme_test function to modify the design and layout of a ggplot2 plot in the R programming language. In case you have additional comments and/or questions, let me know in the comments section.

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