Scatterplots in ggplot2

You will learn the layered syntax of ggplot2 for scatterplots in this section. It also demonstrates how regression lines can be added (compared with the base-R syntax shown in the introductory video).

Label points in the scatter plot

Change the appearance of points and lines

This section describes how to change:

the color and the shape of points
the line type and color of the regression line
the fill color of the confidence interval

# Change the point colors and shapes
# Change the line type and color
ggplot(mtcars, aes(x=wt, y=mpg)) + 
  geom_point(shape=18, color="blue")+
  geom_smooth(method=lm, se=FALSE, linetype="dashed",
             color="darkred")
# Change the confidence interval fill color
ggplot(mtcars, aes(x=wt, y=mpg)) + 
  geom_point(shape=18, color="blue")+
  geom_smooth(method=lm,  linetype="dashed",
             color="darkred", fill="blue")

Note that a transparent color is used, by default, for the confidence band. This can be changed by using the argument alpha : geom_smooth(fill=“blue”, alpha=1)