图例标题的对齐方式ggmap

问题描述

我正在尝试将图例标题移动到ggmap（用于在R中使用ggplot2绘制地图的程序包）的颜色栏中。我有两个问题：

如何使图例标题位于颜色栏的顶部（而不是左侧，如下所示）？
是否可以使颜色条更长？

这是我的代码：

CenterOfMap <- geocode("41.396108,2.059348")
Ciutat_Map <- get_googlemap(c(lon=CenterOfMap$lon,lat=CenterOfMap$lat),zoom = 11,maptype = "terrain",source = "google",color="bw",style=c(feature="all",element="labels",visibility="off"))

Ciutat_Map <- ggmap(Ciutat_Map,extent = "device")
Ciutat_Map <- Ciutat_Map + 
  geom_polygon(aes(x=long,y=lat,fill=TOTAL,group=group),data=Hex_Grid_Pop_data,alpha =0.7) 
Ciutat_Map <- Ciutat_Map + 
  scale_fill_gradientn(colours = c("#e5d5f2","#cdb4db","#b293c2","#9d78ad","#855a96","#724485","#5d2c70"),limits=c(0,1700),oob=squish,space = "Lab",na.value = "transparent",guide = "colourbar")
Ciutat_Map <- Ciutat_Map + 
   theme(legend.position = c(0.90,0.1),legend.direction = "horizontal",legend.title = element_text(size = 16),legend.text = element_text(size = 14)) + 
   labs(fill = "Total Population") 

Ciutat_Map

解决方法

您可以用更详细的规范替换guide = "colourbar"中的scale_fill_gradientn()：

guide = guide_colourbar(title.position = "top",# this changes legend title position
                        barwidth = 20)          # adjust as needed

使用随机生成的数据的插图：

set.seed(123)
df <- data.frame(
  x = runif(100),y = runif(100),z = runif(100,1700)
)

ggplot(df,aes(x,y)) +
  geom_point(aes(fill = z),shape = 21) +
  scale_fill_gradientn(colours = c("#e5d5f2","#cdb4db","#b293c2","#9d78ad","#855a96","#724485","#5d2c70"),limits=c(0,1700),oob=scales::squish,space = "Lab",na.value = "transparent",guide = guide_colorbar(title.position = "top",barwidth = 20)) + 
  theme(legend.position = c(0.90,0.1),legend.justification = c(1,0),legend.direction = "horizontal",legend.title = element_text(size = 16),legend.text = element_text(size = 14)) +
  labs(fill = "Total Population")

ggmap ggplot2 r r