ggmap扩展缩放或边界

Question

我正在尝试解决以下问题。 我使用ggplot2绘制岛屿地图：

island = get_map(location = c(lon = -63.247593, lat = 17.631598), zoom = 14, maptype = "satellite")
islandMap = ggmap(island, extent = "panel", legend = "bottomright")
RL = geom_point(aes(x = longitude, y = latitude), data = data, size = 4, color = "#ff0000")
islandMap + RL

RL点的坐标：

data = data.frame(
    ID = as.numeric(c(1:8)),
    longitude = as.numeric(c(-63.27462, -63.26499, -63.25658, -63.2519, -63.2311, -63.2175, -63.23623, -63.25958)),
    latitude = as.numeric(c(17.6328, 17.64614, 17.64755, 17.64632, 17.64888, 17.63113, 17.61252, 17.62463))
)

现在的问题是，当我使用zoom = 13时，岛上的岛太小了，当我使用zoom = 14时，它完全居中。但是当我绘制RL点时，两个被切断，因为它对东方太多而另一个对西方来说太过分了。我使用边界框查看了一些类似下面的解决方案。但是，我必然会使用卫星图像，因此绑定到Google，它不支持边界框解决方案。

lon = data$longitude
lat = data$latitude
box = make_bbox(lon, lat, f = 0.1)
island = get_map(location = box, zoom = 14, source = "osm")
islandMap = ggmap(island, extent = "panel", legend = "bottomright")
RL = geom_point(aes(x = longitude, y = latitude), data = data, size = 4, color = "#ff0000")
islandMap + RL

如何确保地图与使用zoom = 14一样大，所有点都在图中（加上此处的边距）和卫星图像？

Answer 1

使用this question的答案，我做了以下事情。您可能希望获得缩放= 13的地图，然后想要使用scale_x_continuous()和scale_y_continuous()修剪地图。

library(ggmap)
library(ggplot2)

island = get_map(location = c(lon = -63.247593, lat = 17.631598), zoom = 13, maptype = "satellite")


RL <- read.table(text = "1    17.6328    -63.27462
2    17.64614   -63.26499
3    17.64755   -63.25658
4    17.64632   -63.2519
5    17.64888   -63.2311
6    17.63113   -63.2175
7    17.61252   -63.23623
8    17.62463   -63.25958", header = F)

RL <- setNames(RL, c("ID", "Latitude", "Longitude"))


ggmap(island, extent = "panel", legend = "bottomright") +
geom_point(aes(x = Longitude, y = Latitude), data = RL, size = 4, color = "#ff0000") +
scale_x_continuous(limits = c(-63.280, -63.20), expand = c(0, 0)) +
scale_y_continuous(limits = c(17.60, 17.66), expand = c(0, 0))