怎么将折线图画成间断的，中间自定义点的形状的图

今天在群里无意见看到一个人问，这种图怎么画？我第一反应pch?
后面查了才知道，并不是，而且我也不知道用ggplot2怎么实现，顿时还有点慌！！有提供意见geom_segment(),我心想哇不至于吧，最后才发现原来在基础函数plot中就是一个参数type的问题就解决了

思路来源在bird.so浏览器中搜索R line type然后显示如下

bird.so

set.seed(0); x1 <- rnorm(10); x2 <- rnorm(10); x3 <- rnorm(10)

plot(x1, type = "c", pch = 19, lty = 1, col = 1,
     ylim = range(c(x1,x2,x3)))
points(x2, pch = 4, col = 2) ## only points
lines(x3, lty = 2, col = 3)  ## only lines
legend(6, legend = c("x1", "x2", "x3"),
       pch = c(19, 19, NA), lty = c(1, NA, 2),
       col = c(1,2,3), text.col = c(1,2,3))
legend(x=8,y=2,c("x1","x2","x3"),lty=c(1,NA,2),pch=c(19, 4, NA),
       cex=.8, col=c("blue","red","forestgreen"))

# 然后从上可以看出，拿数据x1举例，结合plot(type = "c") + point(pch = 4)
# 就可以合并一起
plot(x1, type = "c", pch = 19, lty = 1, col = 1,
     ylim = range(c(x1,x2,x3)))  ## 重点需注意type的选项，详细见？plot
points(x1, pch = 4, col = 2) ## only points

间断折线图

另外求赐教ggplot2怎么画这种图，谢谢！