Modifying Aesthetics

Introduction to Data Visualization with ggplot2

Rick Scavetta

Founder, Scavetta Academy

Positions

Adjustment for overlapping

identity
dodge
stack
fill
jitter
jitterdodge
nudge

position = "identity" (default)

ggplot(iris, aes(x = Sepal.Length, 
                 y = Sepal.Width, 
                 color = Species)) + 
  geom_point()

position = "identity" (default)

ggplot(iris, aes(x = Sepal.Length, 
                 y = Sepal.Width, 
                 color = Species)) + 
  geom_point(position = "identity")

position = "jitter"

ggplot(iris, aes(x = Sepal.Length, 
                 y = Sepal.Width, 
                 color = Species)) + 
  geom_point(position = "jitter")

position_jitter()

posn_j <- position_jitter(0.1)

ggplot(iris, aes(x = Sepal.Length, 
                 y = Sepal.Width, 
                 col = Species)) +
  geom_point(position = posn_j)

position_jitter()

posn_j <- position_jitter(0.1, 
                          seed = 136)

ggplot(iris, aes(x = Sepal.Length, 
                 y = Sepal.Width, 
                 color = Species)) + 
  geom_point(position = posn_j)

Set arguments for the position
Consistency across plots & layers

Scale functions

scale_x_*()
scale_y_*()
scale_color_*()
- Also scale_colour_*()
scale_fill_*()
scale_shape_*()
scale_linetype_*()
scale_size_*()

Scale functions

scale_x_continuous()
scale_y_*()
scale_color_discrete()
- Alternatively, scale_colour_*()
scale_fill_*()
scale_shape_*()
scale_linetype_*()
scale_size_*()

scale__()

ggplot(iris, aes(x = Sepal.Length, 
                 y = Sepal.Width, 
                 color = Species)) + 
  geom_point(position = "jitter") +
  scale_x_continuous("Sepal Length") +
  scale_color_discrete("Species")

The limits argument

ggplot(iris, aes(x = Sepal.Length, 
                  y = Sepal.Width, 
                 color = Species)) + 
  geom_point(position = "jitter") +
  scale_x_continuous("Sepal Length", 
                     limits = c(2,8)) +
  scale_color_discrete("Species")

The breaks argument

ggplot(iris, aes(x = Sepal.Length, 
                  y = Sepal.Width, 
                 color = Species)) + 
  geom_point(position = "jitter") +
  scale_x_continuous("Sepal Length", 
                     limits = c(2, 8), 
                     breaks = seq(2, 8, 3)) +
  scale_color_discrete("Species")

The expand argument

ggplot(iris, aes(x = Sepal.Length, 
                  y = Sepal.Width, 
                 color = Species)) + 
  geom_point(position = "jitter") +
  scale_x_continuous("Sepal Length", 
                     limits = c(2, 8), 
                     breaks = seq(2, 8, 3),
                     expand = c(0, 0)) +
  scale_color_discrete("Species")

The labels argument

ggplot(iris, aes(x = Sepal.Length, 
                  y = Sepal.Width, 
                 color = Species)) + 
  geom_point(position = "jitter") +
  scale_x_continuous("Sepal Length", 
                     limits = c(2, 8), 
                     breaks = seq(2, 8, 3),
                     expand = c(0, 0), 
                     labels = c("Setosa", 
                               "Versicolor", 
                               "Virginica")) +
  scale_color_discrete("Species")

labs()

ggplot(iris, aes(x = Sepal.Length, 
                 y = Sepal.Width, 
                 color = Species)) +
  geom_point(position = "jitter") +
  labs(x = "Sepal Length", 
       y = "Sepal Width", 
       color = "Species")

Let's try it out!

Introduction to Data Visualization with ggplot2

Modifying Aesthetics

Positions

position = "identity" (default)

position = "identity" (default)

position = "jitter"

position_jitter()

position_jitter()

Scale functions

Scale functions

scale_*_*()

The limits argument

The breaks argument

The expand argument

The labels argument

labs()

Let's try it out!

scale__()