ggplot(data3, aes(x =cumulative, y = var_cost))+ geom_point( aes (colour = fuel_type))+ geom_vline(aes(xintercept=average, linetype= "average"), color = "black")+ geom_vline(aes(xintercept=winter, linetype= "winter"), color = "blue")+ geom_vline(aes(xintercept=summer, linetype = "summer"), color = "red")+ scale_linetype_manual(name = "Load", values = c("average" = 1, "winter" = 1, "summer" = 1), guide = guide_legend(override.aes = list(colour = c("black", "blue", "red")))) + theme_update(plot.title = element_text(hjust = 0.5))+ ggtitle("Generation Supply Curve")+ xlab("Cumulative Capacity")+ ylab("Variable Costs")