Scatter Plots - R Graphics - page 101

Figure 5-6. Left: scatter plot with the shape aesthetic set to a custom value; right: with a variable
mapped to shape, using a custom shape palette
If you have mapped a variable to shape , use scale_shape_manual() to change the shapes:
# Use slightly larger points and use a shape scale with custom values
ggplot(heightweight, aes(x = ageYear, y = heightIn, shape = sex)) +
geom_point(size = 3 ) + scale_shape_manual(values = c( 1 , 4 ))
Discussion
Figure 5-7 shows the shapes that are available in R graphics. Some of the point shapes (1-14)
have just an outline, some (15-20) are solid, and some (21-25) have an outline and fill that can
be controlled separately. (You can also use characters for points.)
For shapes 1-20, the color of the entire point—even the points that are solid—is controlled by
the colour aesthetic. For shapes 21-25, the outline is controlled by colour and the fill is con-
trolled by fill .