如何将两个地图合并为一个？ [英] How to join two maps into one in r?

问题描述

我想知道是否有办法将两个sp类地图合并为一个。

例如瑞典+挪威，有一个代码（shp数据是从 http://www.gadm.org/country ）：

  library（maptools） 
 
 mapa_shp_swe<  -  readShapePoly（C：/r/SWE_adm/SWE_adm0.shp）
 mapa_map_swe<  -  fortify（mapa_shp_swe）; 
 
 swe< -  ggplot（mapa_map_swe，aes（x = long，y = lat，group = group））+ 
 geom_path（size = 1）+ 
 theme_bw（）
 
 mapa_shp_nor< -  readShapePoly（C：/r/NOR_adm/NOR_adm0.shp）
 mapa_map_nor < -  fortify（mapa_shp_nor）
 
也不<-ggplot（mapa_map_nor，aes（x = long， y = lat，group = group））+ 
 geom_path（size = 1）+ 
 theme_bw（）
  

我个人倾向于在 rgdal 中使用 spRbind（） / code>包，因为我总是在处理shapefile时加载它。

 ＃ensure shapefil （chpa_shp_swe，polygons））
 newShape < -  spChFIDs（mapa_shp_nor，as.character（n））
 
＃实际连接
 newShape < -  spRbind（newShape，mapa_shp_swe）
 
＃如果您愿意，您可以编写它
 writeOGR（sweNor，dsn =shapes /，layer =newShape，
 driver =ESRI Shapefile）
  

在 shapes / 目录中合并了两个原始形状文件的shapefile，名为 sweNor 。

至于绘制城市，@cmbarbu指出这应该是一个单独的问题，但您可以尝试添加以下代码：

  ggplot（newShape，aes（x = long，y = lat，group = group））+ 
 geom_path（size = 1）+ 
 geom_point（data = cities， aes（x = x，y = y））+ 
 theme_bw（）
  

没有经过测试，所以没有保证！

I am wondering if there is a way to join two maps of class "sp" into one.

For example Sweden + Norway, there is a code (shp data were downloaded from: http://www.gadm.org/country):

library(maptools)

mapa_shp_swe <- readShapePoly("C:/r/SWE_adm/SWE_adm0.shp")
mapa_map_swe <- fortify(mapa_shp_swe)

swe <- ggplot(mapa_map_swe, aes(x = long, y = lat, group=group)) + 
  geom_path(size=1) +
  theme_bw()

mapa_shp_nor <- readShapePoly("C:/r/NOR_adm/NOR_adm0.shp")
mapa_map_nor <- fortify(mapa_shp_nor)

nor <- ggplot(mapa_map_nor, aes(x = long, y = lat, group=group)) + 
  geom_path(size=1) +
  theme_bw()

解决方案

Personally I tend to use the spRbind() function in the rgdal package, because I tend to have this loaded when working with shapefiles anyway.

# ensure shapefiles have unique ids
n <- length(slot(mapa_shp_swe, "polygons"))
newShape <- spChFIDs(mapa_shp_nor, as.character(n))

# the actual join
newShape <- spRbind(newShape, mapa_shp_swe)

# you can then write it if you wish
writeOGR(sweNor, dsn = "shapes/", layer = "newShape",
         driver = "ESRI Shapefile")

Which should write a new shapefile called sweNor with both original shapefiles merged in the shapes/ directory.

As for plotting the cities, as @cmbarbu points out this should really be asked as a separate question, but you could try adding the following code:

ggplot(newShape, aes(x = long, y = lat, group=group)) + 
    geom_path(size=1) + 
    geom_point(data = cities, aes(x = x, y = y)) +
    theme_bw() 

I haven't tested this yet so there's no guarantee!

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