Plotting the africa and non africa model on GDP and road ruggeness. Chapter on "Coditional Manaies"

statistical_rethininking_fig8_4.R

## Assuming we already have the model describe on page 246 - 247
## Here is a possible way to get the graph describe on figure 8.5 from Statistical Rethinking Figure 8.4

plot(NULL, xlim=c(0,1), ylim=c(0.5, 1.5), xlab="rudgeness", ylab="gdp log std")

points(dd$rugged_std[dd$cont_africa==1], dd$log_gdp_std[dd$cont_africa==1], col="blue")
points(dd$rugged_std[!dd$cont_africa], dd$log_gdp_std[!dd$cont_africa], col="black")

lines(rudge_seq, mu.NotAfrica_mu)
shade(mu.NotAfrica_ci, rudge_seq)

lines(rudge_seq, mu.Africa_mu)
shade(mu.Africa_ci, rudge_seq)