ggplot2 中使用 viridis 的气泡图图例颜色

Question

您好，我希望此气泡图图例中的气泡以图表中使用的绿色颜色着色。我想出了如何使用简单的颜色（例如这里的橙色）自定义颜色，但我不确定如何使用 viridis 颜色或更一般的任何调色板覆盖 aes。

指南（大小=guide_legend（覆盖.aes = 列表（颜色=“橙色”）））

# Libraries
library(ggplot2)
library(dplyr)

# Get the world polygon and extract UK
library(maps)
UK <- map_data("world") %>% filter(region=="UK")

# Get a data frame with longitude, latitude, and size of bubbles (a bubble = a city)
data <- world.cities %>% filter(country.etc=="UK")

# virids package for the color palette
library(viridis)

# Do bubble map and use viridis as color palette 
ggplot() +
  geom_polygon(data = UK, aes(x=long, y = lat, group = group), fill="grey", alpha=0.3) +
  geom_point( data=data, aes(x=long, y=lat, size=pop, color=pop)) +
  scale_size_continuous(range=c(1,12)) +
  scale_color_viridis(trans="log") +
  guides(size=guide_legend(override.aes = list(color= "orange"))) + 
  theme_void() + ylim(50,59) + coord_map() 

Answer 1

You can use the viridis function to pass colors (in this case 3 colors) from the viridis palette to override.aes like you where doing with orange:

ggplot() +
  geom_polygon(data = UK, aes(x=long, y = lat, group = group), fill="grey", alpha=0.3) +
  geom_point( data=data, aes(x=long, y=lat, size = pop, color = pop)) +
  scale_size_continuous(range=c(1,12)) +
  scale_color_viridis(trans="log") +
  guides(size=guide_legend(override.aes = list(color = viridis(3)))) +
  theme_void() + ylim(50,59) + coord_map()