2.6 Other aesthetic attributes

• color, shape and size can be mapped to variables in the data

The class variable of the mpg dataset has seven unique values. The plot can assign a specific color to each value by mapping class to color within the aesthetic function.

## # A tibble: 7 × 1
##   class     
##   <chr>     
## 1 compact   
## 2 midsize   
## 3 suv       
## 4 2seater   
## 5 minivan   
## 6 pickup    
## 7 subcompact

ggplot(mpg, aes(displ, hwy, color = class)) +
  geom_point()

Including a color assignment outside the aesthetic of the geometry layer will make all of the points that color.

ggplot(mpg, aes(displ, hwy)) +
  geom_point(color = "blue")

Mapping a variable to shape and color adds some diversity and information to the plot.

ggplot(mpg, aes(displ, hwy, shape = drv, color = drv)) + 
  geom_point()

Mapping a variable to size can also add some new insights.

ggplot(mpg, aes(manufacturer, drv, size = displ)) +
  geom_point() +
  theme(axis.text.x = element_text(angle = 90))

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