ggmap扩展缩放或边界 [英] ggmap extended zoom or boundaries

问题描述

我正在尝试解决以下问题。
我用ggplot2来绘制一个岛屿的地图：

$ p $ island $ get_map（location = c（lon = - ） （a，b，c，c，b，b，b，b，b，b，b，b，b，b，b，b，b，b，b，b） = 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，该岛太小，当我使用zoom = 14时，它完全居中。但是当我绘制RL点时，其中两个会被切断，因为它对东方太多而对西方太多太多。我使用边界框来查找类似于下面的一些解决方案。但是，我必然会使用卫星图像，因此必然会受到Google的限制，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 =纬度），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（加上一个边距）和卫星图像？ 解决方案

使用我从

I am trying to fix the following problem. I use ggplot2 to plot a map of an island:

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

Coordinates of the RL points:

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))
)

Now the problem is that when I use zoom = 13 the island is too small in the plot and when I use zoom = 14 it is perfectly centered. But when I plot the RL points, two get cut off because its too much to the East and the other one too much to the West. I looked some solutions up like the following one, using a boundary box. However, I am bound to using satellite imagery, so bound to Google, which doesn't support the boundary box solution.

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

How can I make sure that the map is as big as using zoom = 14, all the points are within the plot (plus a margin around this) and satellite imagery?

解决方案

Using my answer from this question, I did the following. You may want to get a map with zoom = 13, and then you want to trim the map with scale_x_continuous() and scale_y_continuous().

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))

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