GGMAP传奇未显示

Question

我有两个数据范围都记录了前10个电台骑手的走了。一个是为了休闲骑手，另一个是为成员骑手。两个数据范围都包含列“站”，“ freq”，“ Latitude”，“经度”。我能够使用GGMAP绘制图形，显示两个数据范围内的电台位置，但无法显示传说。 R scripe如下所示：

library(ggplot2)
library(rstudioapi)
library(ggmap)

map_location <- c (lon =  -87.623177, lat = 41.881832)

chicago_map_zoom <- get_map (location = map_location, 
                        maptype = 'roadmap', 
                        color='bw', 
                        source='google', 
                        zoom=13,
)

chicago_plot <- ggmap(chicago_map_zoom) +
  geom_point (data = casual_top_station,
              aes (x = longitude,
                   y = latitude),
              color = "red",
              shape = 15,
              alpha = 0.5,
              size = 3) +
  geom_point (data = member_top_station,
              aes (x = longitude,
                   y = latitude),
              color = "blue",
              shape = 16,
              alpha = 0.5,
              size = 2) +
  scale_color_identity (name = "Subscription type",
                        breaks = c("red","blue"),
                        labels = c("Casual","Member"),
                        guide = "legend") +
  theme (axis.ticks = element_blank(),
         axis.text = element_blank(),
         axis.title = element_blank()) +
  labs (title = "Top 10 casual and member rider stations",
        subtitle = "Both start and end stations")

结果图： chicago_map

Answer 1

而不是使用scale_color_identity ...为了设置颜色，形状和大小的值，我建议您首先将ID列列到您的data.frames
然后可以在aes内的美学上映射。之后，通过scale_xxx_manual函数系列设置所需的颜色，形状和大小。

使用一些虚假数据来点：

library(ggplot2)
library(ggmap)

casual_top_station <- data.frame(
  longitude = -87.65,
  latitude = 41.9
)

member_top_station <- data.frame(
  longitude = -87.65,
  latitude = 41.86
)

casual_top_station$id <- "Casual"
member_top_station$id <- "Member"
legend_title <- "Subscription type"

base <- ggmap(chicago_map_zoom) +
  scale_color_manual(values = c(Casual = "red", Member = "blue")) +
  scale_shape_manual(values = c(Casual = 15, Member = 16)) +
  scale_size_manual(values = c(Casual = 3, Member = 2)) +
  theme(
    axis.ticks = element_blank(),
    axis.text = element_blank(),
    axis.title = element_blank()
  ) +
  labs(
    title = "Top 10 casual and member rider stations",
    subtitle = "Both start and end stations",
    color = legend_title, shape = legend_title, size = legend_title
  )

base + 
  geom_point(
    data = casual_top_station,
    aes(
      x = longitude,
      y = latitude,
      color = id, shape = id, size = id
    ),
    alpha = 0.5
  ) +
  geom_point(
    data = member_top_station,
    aes(
      x = longitude,
      y = latitude,
      color = id, shape = id, size = id
    ),
    alpha = 0.5
  )

，为了进一步简化代码例如dplyr :: bind_rows，它将仅通过一个geom_point添加您的点。

top_station <- dplyr::bind_rows(casual_top_station, member_top_station)

base + 
  geom_point(
    data = top_station,
    aes(
      x = longitude,
      y = latitude,
      color = id, shape = id, size = id
    ), alpha = .5)