I have plotted 4 line on a chart:
ggplot() +
geom_line(benchmark, mapping=aes(Date, EM))+
geom_line(portfolio, mapping=aes(Date, EM), color="red") +
geom_line(benchmark, mapping=aes(Date, CB))+
geom_line(portfolio, mapping=aes(Date, CB), color="red")
How can I add a legend to this?