Comparing probits and logits

You learned about probit and logit link function in the previous chapter. Now, you will learn how to plot them together with ggplot2. The purpose of this exercise is to show you that the two are often very similar and also to show you how to change link functions with ggplot2. Your plot, gg_jitter, has been loaded for you and you will use this with geom_smooth(). Also, you will change the colors of your curves and remove the shaded areas to make the plot easier to read.

This exercise is part of the course

Generalized Linear Models in R

View Course

Exercise instructions

  • Plot a probit curve by setting the first family to use a probit link using binomial(link = 'probit'), the color to 'red', and se to FALSE.
  • Plot a logit curve by setting the first family to use a logit link using binomial(link = 'logit'), the color to 'blue', and se to FALSE.

Hands-on interactive exercise

Have a go at this exercise by completing this sample code.

# Add geom_smooth() lines for the probit and logit link functions
gg_jitter + 
	___(method = 'glm', 
                method.args = list(___), 
                color = '___', se = ___) +
	___(method = 'glm', 
                method.args = list(___), 
                color = '___', se = ___)