Data Science, Machine Learning, Rstats, Regression.
fitted values for simulating QI dist_range <- min(cars.poly$dist):max(cars.poly$dist) # Estimate, simulate, and plot zelig(speed ~ dist + dist_2, data = cars.poly, model = 'ls', cite = FALSE) %>% setx(dist = dist_range, dist_2 = dist_range^2) %>% sim() %>% plot() Note that in setx we included both