GGPLOT Point Shapes Best Tips

Key R functions

• geom_point(aes(x, y), data = NULL, shape = 19, color = "black", size = 1): ggplot2 function to create a scatter plot.
• scale_shape_manual(), scale_color_manual() and scale_size_manual(): ggplot2 functions to set manually point shape, color and size.

List of point symbols

The most commonly used pch values in R, include:

The function below illustrates the different point shape values. First install the ggpubr package (install.packages("ggpubr")), and then type this:

ggpubr::show_point_shapes()

Demo dataset

We’ll use the R built-in datasets: iris.

head(iris, 3)

##   Sepal.Length Sepal.Width Petal.Length Petal.Width Species
## 1          5.1         3.5          1.4         0.2  setosa
## 2          4.9         3.0          1.4         0.2  setosa
## 3          4.7         3.2          1.3         0.2  setosa

Basic scatter plots

Create a scatter plot and change points shape, color and size:

library(ggplot2)
# Change shape, color and size
ggplot(iris, aes(Sepal.Length, Sepal.Width)) +
  geom_point(shape = 18, color = "#FC4E07", size = 3)+
  theme_minimal()

# Change background fill and line color
ggplot(iris, aes(Sepal.Length, Sepal.Width)) +
  geom_point(shape = 21, fill = "lightgray",
             color = "black", size = 3)+
  theme_minimal()

Scatter plot with multiple groups

It’s also possible to change point shapes and colors by groups. In this case, ggplot2 will use automatically a default color palette and point shapes. You can change manually the appearance of points using the following functions:

• scale_shape_manual() : to change manually point shapes
• scale_color_manual() : to change manually point colors
• scale_size_manual() : to change manually the size of points

# Change point shapes and colors by groups
ggplot(iris, aes(Sepal.Length, Sepal.Width)) +
  geom_point(aes(shape = Species, color = Species), size = 3) +
  scale_shape_manual(values = c(5, 16, 17)) +
  scale_color_manual(values = c("#00AFBB", "#E7B800", "#FC4E07"))+
  theme_minimal() +
  theme(legend.position = "top")

Conclusion

This article describes how to change ggplot point shapes.

• Display the different point symbols in R:

ggpubr::show_point_shapes()

• Change point shapes in ggplot2. Use shape, size and color in geom_point():

library(ggplot2)
ggplot(iris, aes(Sepal.Length, Sepal.Width)) +
  geom_point(shape = 18, color = "#FC4E07", size = 3)+
  theme_minimal()