在无边界地图上画点

Question

library(ggplot2)
library(ggmap)
data <- read.table(file = "data.txt", sep = ",", col.names = c("lat", "lon", "place_name"), fill=FALSE, strip.white=TRUE)

# getting the map
mapgilbert <- get_map(location = c(lon = mean(data$lon), lat = mean(data$lat)),
              zoom = "auto" , maptype = "roadmap", scale = 2, color = "bw")

# plotting the map with some points on it
ggmap(mapgilbert, extent = "device") +
  geom_point(data = data, aes(x = lon, y = lat, fill = place_name), size = 0.5, shape = 22) +
  guides(fill=FALSE, alpha=FALSE, size=FALSE)

这将产生不同颜色的点（根据它们的名称）。像这样：

不过，我想去掉点的黑边。有办法吗？

Answer 1

尝试不同的 shape：

data <- data.frame(lat=52.5176736, lon=13.3895097)
library(ggmap)
library(ggplot2)
mapgilbert <- get_map(location = c(lon = mean(data$lon), lat = mean(data$lat)),
              zoom = "auto" , maptype = "roadmap", scale = 2, color = "bw")
ggmap(mapgilbert, extent = "device") +
  geom_point(data = data, aes(x = lon, y = lat), size = 6, shape = 16, color="red") +
  guides(fill=FALSE, alpha=FALSE, size=FALSE)

或在使用shape = 21时将color设置为NA：

ggmap(mapgilbert, extent = "device") +
  geom_point(data = data, aes(x = lon, y = lat), size = 6, shape = 21, color=NA, fill = "red") +
  guides(fill=FALSE, alpha=FALSE, size=FALSE)

在无边界地图上画点

Draw Point on Map Without Border

r

ggplot2

ggmap