r - 使用ggplot2在地图上绘制条形图？

Question

我想使用 ggplot2 为地图上的每个位置生成一个条形图，就像 xingmowang 使用基本图形和一些包所做的那样：

http://nzprimarysectortrade.wordpress.com/2011/10/02/let-r-fly-visualizing-export-data-using-r/

这与在情节中嵌入微型情节有关。

目前，我能做的最好的是将值与抖动点图中的点大小匹配：

require(ggplot2)
require(maps)

#Get world map info
world_map <- map_data("world")

#Creat a base plot
p <- ggplot() + coord_fixed()

#Add map to base plot
base_world <- p + geom_polygon(data=world_map,
                               aes(x=long,
                                   y=lat,
                                   group=group))


#Create example data
geo_data <- data.frame(long=c(20,20,100,100,20,20,100,100),
                       lat=c(0,0,0,0,0,0,0,0),
                       value=c(10,30,40,50,20,20,100,100),
                       Facet=rep(c("Facet_1", "Facet_2"), 4),
                       colour=rep(c("colour_1", "colour_2"), each=4))

#Creat an example plot
map_with_jitter <- base_world+geom_point(data=geo_data,
                                            aes(x=long,
                                                y=lat,
                                                colour=colour,
                                                size=value),
                                         position="jitter",
                                         alpha=I(0.5))

#Add faceting
map_with_jitter <- map_with_jitter + facet_wrap(~Facet)

map_with_jitter <- map_with_jitter + theme(legend.position="none")

print(map_with_jitter)

使用不优雅的解决方法：

subset_data <- geo_data[geo_data$Facet=="Facet_1" &
                          geo_data$long=="20",]
subplot <- qplot(data=subset_data,
                 x=colour,
                 y=value,
                 fill=colour,
                 geom="bar",
                 stat="identity")+theme(legend.position="none")

print(base_world)
print(subplot, vp=viewport((200+mean(subset_data$long))/400,(100+mean(subset_data$lat))/200 , .2, .2))

Answer 1

2016-12-23 更新：ggsubplot-package 不再积极维护，并存档在 CRAN 上：

软件包“ggsubplot”已从 CRAN 存储库中删除。>
可以从存档中获得以前可用的版本。>
应维护者 garrett@rstudio.com 的要求于 2016-01-11 存档。

ggsubplot不适用于 R 版本 >= 3.1.0。安装 R 3.0.3 以运行以下代码：

---

您确实可以通过ggsubplot像 Baptiste 建议的软件包来实现这一点。

library(ggsubplot)
library(ggplot2)
library(maps)
library(plyr)

#Get world map info
world_map <- map_data("world")

#Create a base plot
p <- ggplot()  + geom_polygon(data=world_map,aes(x=long, y=lat,group=group))

# Calculate the mean longitude and latitude per region, these will be the coördinates where the plots will be placed, so you can tweak them where needed.
# Create simulation data of the age distribution per region and merge the two.

centres <- ddply(world_map,.(region),summarize,long=mean(long),lat=mean(lat))
mycat <- cut(runif(1000), c(0, 0.1, 0.3, 0.6, 1), labels=FALSE) 
mycat <- as.factor(mycat)
age <- factor(mycat,labels=c("<15","15-30","20-60",">60"))
simdat <- merge(centres ,age)
colnames(simdat) <- c( "region","long","lat","Age" )

# Select the countries where you want a subplot for and plot
simdat2 <- subset(simdat, region %in% c("USA","China","USSR","Brazil", "Australia"))
(testplot <- p+geom_subplot2d(aes(long, lat, subplot = geom_bar(aes(Age, ..count.., fill = Age))), bins = c(15,12), ref = NULL, width = rel(0.8), data = simdat2))

结果：