手动定义的颜色不显示图例

Question

我在用ggplot2做一个地图路线。这是代码。

colombia_map <- ggplot(data = colombia, mapping = aes(x = long, y = lat, group = group)) + 
  geom_polygon(fill = 'white', color = 'black', size = 1) + 
  coord_quickmap() +
  theme(panel.grid = element_blank(), panel.background = element_blank())

colombia_map1 <- colombia_map +
  geom_point(data = nombres[2:3],
             aes(x = lon, y = lat),
             colour = "Black",
             size = 2, inherit.aes = F) +
    geom_curve(data = avianca,
             aes(x = flon, y = flat, xend = tlon, yend = tlat, color = "Avianca"),
             col = "red",
             size = 0.5,
             curvature = 0.2, inherit.aes = F) +
  geom_curve(data = latam,
             aes(x = flon, y = flat, xend = tlon, yend = tlat, color = "Latam"),
             col = "darkblue",
             size = 0.5,
             curvature = 0.2, inherit.aes = F) +
  geom_curve(data = easy,
             aes(x = flon, y = flat, xend = tlon, yend = tlat, color = "Easy Fly"),
             col = "darkorange",
             size = 0.5,
             curvature = 0.2, inherit.aes = F, show.legend = T) +
  geom_curve(data = viva,
             aes(x = flon, y = flat, xend = tlon, yend = tlat, color = "Viva Air"),
             col = "gold",
             size = 0.5,
             curvature = 0.2, inherit.aes = F, show.legend = T) +
  geom_curve(data = satena,
             aes(x = flon, y = flat, xend = tlon, yend = tlat, color = "Satena"),
             col = "olivedrab",
             size = 0.5,
             curvature = 0.2, inherit.aes = F, show.legend = T) +
  geom_curve(data = wingo,
             aes(x = flon, y = flat, xend = tlon, yend = tlat, color = "Wingo"),
             col = "purple",
             size = 0.5,
             curvature = 0.2, inherit.aes = F, show.legend = T) +
  geom_text_repel(data = nombres,
                  aes(x = lon, y = lat, label = Origen),
                  colour = "black",
                  size = 3.5, inherit.aes = F) +
  scale_color_manual(name = "Operadores",
                     breaks = c("Avianca", "Latam", "Viva Air", "Easy Fly", "Satena", "Wingo"),
                     values = c("Avianca" = "red", "Latam" = "darkblue", "Viva Air" = "gold",
                                "Easy Fly" = "darkorange", "Satena" = "olivedrab", 
                                "wingo" = "purple")) +
  theme(axis.line = element_blank(),
        axis.text.x = element_blank(),
        axis.text.y = element_blank(),
        axis.title.x = element_blank(),
        axis.title.y = element_blank(),
        axis.ticks = element_blank(),
        rect = element_rect(fill = "transparent")) 

这是输出结果

问题是我尝试了所有的方法 但我不明白为什么图例没有出现在地图上。我尝试了一般贴图中的美学和每个geom_curve中的美学，但是没有任何效果！有什么办法可以解决这个问题吗？

有什么办法可以解决这个问题吗？

Answer 1

在没有数据的情况下，这很难复制，但这里有一个玩具的例子，可以做一些类似你想做的事情。

library(ggplot2)
ggplot() +
  geom_line(data = economics, aes(x = date, y = psavert, colour = "PSAVERT")) +
  geom_line(data = economics, aes(x = date, y = uempmed, colour = "UEMPMED")) +
  scale_colour_manual(values = c("PSAVERT"="blue","UEMPMED"="red"))

你必须把颜色值放在 aes(...)但你可以在里面明确地定义标签，它将直接映射到图例。然后你可以使用 scale_colour_manual(values = c(....). 但在你的情况下，你覆盖了 aes(..) 调用你的显式颜色调用，如。

geom_curve(data = latam,
             aes(x = flon, y = flat, xend = tlon, yend = tlat, color = "Latam"),
             col = "darkblue",
             size = 0.5,
             curvature = 0.2, inherit.aes = F)

所以考虑到这一点，你可以用更简单的方式重写你的代码。

colombia_map <- ggplot(data = colombia, mapping = aes(x = long, y = lat, group = group)) + 
  geom_polygon(fill = 'white', color = 'black', size = 1) + 
  coord_quickmap() +
  theme(panel.grid = element_blank(), panel.background = element_blank())

colombia_map1 <- colombia_map +
  geom_point(data = nombres[2:3],
             aes(x = lon, y = lat),
             colour = "Black",
             size = 2, inherit.aes = F) +
    geom_curve(data = avianca,
             aes(x = flon, y = flat, xend = tlon, yend = tlat, color = "Avianca"),
             size = 0.5,
             curvature = 0.2) +
  geom_curve(data = latam,
             aes(x = flon, y = flat, xend = tlon, yend = tlat, color = "Latam"),
             size = 0.5,
             curvature = 0.2) +
  geom_curve(data = easy,
             aes(x = flon, y = flat, xend = tlon, yend = tlat, color = "Easy Fly"),
             size = 0.5,
             curvature = 0.2) +
  geom_curve(data = viva,
             aes(x = flon, y = flat, xend = tlon, yend = tlat, color = "Viva Air"),
             size = 0.5,
             curvature = 0.2) +
  geom_curve(data = satena,
             aes(x = flon, y = flat, xend = tlon, yend = tlat, color = "Satena"),
             size = 0.5,
             curvature = 0.2) +
  geom_curve(data = wingo,
             aes(x = flon, y = flat, xend = tlon, yend = tlat, color = "Wingo"),
             size = 0.5,
             curvature = 0.2) +
  geom_text_repel(data = nombres,
                  aes(x = lon, y = lat, label = Origen),
                  colour = "black",
                  size = 3.5, inherit.aes = F) +
  scale_color_manual(name = "Operadores",
                     values = c("Avianca" = "red", "Latam" = "darkblue", "Viva Air" = "gold",
                                "Easy Fly" = "darkorange", "Satena" = "olivedrab", 
                                "wingo" = "purple")) +
  theme(axis.line = element_blank(),
        axis.text.x = element_blank(),
        axis.text.y = element_blank(),
        axis.title.x = element_blank(),
        axis.title.y = element_blank(),
        axis.ticks = element_blank(),
        rect = element_rect(fill = "transparent")) 

那就是 应 工作，但没有一个完全可复制的例子，很难保证。今后，请分享你的数据结构，使用了 dput().