R语言中abline函数

1、

plot(0:10, 0:10, pch = 16, col = "red", xaxs = "i", yaxs = "i")
abline(h = 5, lwd = 5)     ## 高度

2、

plot(0:10, 0:10, pch = 16, col = "red", xaxs = "i", yaxs = "i")
abline(v = 5, lwd = 5)     ## 水平

3、

plot(0:10, 0:10, pch = 16, col = "red", xaxs = "i", yaxs = "i")
abline(a = 1, b = 2, lwd = 5)      ## y = a + bx