xintercept, yintercept, slope, intercept : 控制线位置的参数。如果设置了这些,数据、映射和显示图例被覆盖 示例\实例: p < - ggplot(mtcars, aes(wt, mpg)) + geom_point()# Fixed valuesp + geom_vline(xintercept = 5)p + geom_vline(xintercept = 1:5)p + geom_hline(yintercept = 20)...