Overview of this book

R Graph Essentials
Credits
www.PacktPub.com
Preface
Free Chapter
Base Graphics in R – One Step at a Time
Creating Graphs with ggplot
Index

Creating boxplots

In this section, we will learn how to create boxplots. Using the medical dataset, let's produce a simple boxplot of patient weight before treatment, grouped by the three levels of treatment. We use the syntax `geom = "boxplot"` and again we choose a nice color from the Hexadecimal Color Chart. Enter the following syntax:

```qplot(TREATMENT, WEIGHT_2, data = T,   geom = "boxplot",   xlab = " TREATMENT", ylab = "WEIGHT (kg)", fill = I("#99CCFF"))
```

Here is the boxplot:

If we do not wish to create a grouped boxplot and want a boxplot of all of the data taken together, we simply omit the categorical variable from the `qplot()` command. Anyway, within any boxplot, we can include the data as points—positioned according to the levels of the factor variable. Simply include `"point"` within `geom` as follows:

```qplot(TREATMENT, WEIGHT_2, data = T, geom = c("boxplot","point"),xlab = "TREATMENT", ylab = "WEIGHT (kg)", fill =I("#669900"))
```

The boxplot, along with the raw data, looks like this:

Including...