Plotting residual densities - ggplot2

density-02.R

ggplot(mod, aes(x=mod$residuals)) +
  geom_density(fill="blue", colour=NA, alpha=.2) +
  geom_line(stat = "density") +
  expand_limits(y = 0) +
  ggtitle("Density plot of residuals") +
  theme(plot.title = element_text(hjust = 0.5)) +
  xlab("Residual") +
  ylab("Density")