Data Visualization: Scatter Plots

viz_scatter.R

# scatter plot
plot(mtcars$disp, mtcars$mpg)

# add title and axis labels
plot(mtcars$disp, mtcars$mpg,
     main = 'Displacement vs Miles Per Gallon',
     xlab = 'Displacement', ylab = 'Miles Per Gallon')

# point shape
plot(mtcars$disp, mtcars$mpg, pch = 6)

# shape  based on number of levels of a third variable
plot(mtcars$disp, mtcars$mpg, pch = nlevels(factor(mtcars$cyl)))

# shape based on a third categorical variable
plot(mtcars$disp, mtcars$mpg, pch = unclass(mtcars$cyl))

# point size
plot(mtcars$disp, mtcars$mpg, cex = 1.5)

# color
# shape between 0 and 21
plot(mtcars$disp, mtcars$mpg, pch = 5, col = 'blue', bg = 'red')

# shape between 22 and 25
plot(mtcars$disp, mtcars$mpg, pch = 24, col = 'red', bg = 'blue')

# color based on a third variable
plot(mtcars$disp, mtcars$mpg, pch = 5, col = factor(mtcars$cyl))