R-squared for a Bayesian Model
Now let's calculate the R-squared for a Bayesian model so we can assess the predictions of models estimated with stan_glm. The stan_model object is already loaded.
This exercise is part of the course
Bayesian Regression Modeling with rstanarm
Exercise instructions
- Calculate the variance of the residuals of
stan_model - Calculate the variance of the fitted values of
stan_model - Calculate the R-squared
Hands-on interactive exercise
Have a go at this exercise by completing this sample code.
# Save the variance of residulas
ss_res <- ___(___(stan_model))
# Save the variance of fitted values
ss_fit <- ___(___(stan_model))
# Calculate the R-squared
1 - (___ / (___ + ___))