R 如何在两点之间使用geom_hline

我正在画一个拉玛钱德兰的情节，我想在两点之间画一条线。我正在使用以下代码：

 ggplot(result) + 
  scale_x_continuous(limits = c(-180,180), breaks = seq(-180,180,40), expand=c(0,0)) +
  scale_y_continuous(limits = c(-180,180), breaks = seq(-180,180,40), expand=c(0,0)) +
  geom_hex(aes(x, y), bins = 500) +
  geom_vline(xintercept = 0, colour="red", linetype = "longdash") +
  scale_fill_gradientn("", colours = rev(rainbow(10, end = 4/6))) + ylab(expression(paste(psi))) + xlab(expression(paste(phi)))

我有这个：

但我想再画两条水平线，如下图所示：

---

我使用了hline，但不知道如何在两点之间定义它。

使用

geom\u段

df <- data.frame(x1 = 0, x2 = -180, y1 = 0, y2 = 0) #Data frame with the points

  ggplot(result) + 
  scale_x_continuous(limits = c(-180,180), breaks = seq(-180,180,40), expand=c(0,0)) +
  scale_y_continuous(limits = c(-180,180), breaks = seq(-180,180,40), expand=c(0,0)) +
  geom_hex(aes(x, y), bins = 500) +
  geom_vline(xintercept = 0, colour="red", linetype = "longdash") +
  geom_segment(aes(x = x1, y = y1, xend = x2, yend = y2, colour = "segment"), data = df)+
  scale_fill_gradientn("", colours = rev(rainbow(10, end = 4/6))) + ylab(expression(paste(psi))) + xlab(expression(paste(phi)))

---

df在基本图形或晶格图形中，两点之间的“线”称为“段”。似乎确实存在geom_段gglot2函数。162次点击搜索
[r]ggplot2段
@42-是！。谢谢，我找到了答案。