在R中将SpatialPolygonsDataFrame导出为geojson或topojson

问题描述

我正在尝试将伦敦地方当局的geojson转换为十六进制制图，其中每个六边形代表一个地方当局。它在R中有效，但是当我尝试将生成的hexgrid导出为geojson或topojson时，出现以下错误：

Error in sp::SpatialpolygonsDataFrame(polys,data = input@data) : 
  row.names of data and polygons IDs do not match

这是代码。我正在使用geogrid生成网格，并使用geojsonio将生成的数据帧导出到geojson或topojson：

library(geogrid)
library(geojsonio) # version 0.9.0

df <- read_polygons(system.file("extdata","london_LA.json",package = "geogrid"))
# you can get the json file from here: https://github.com/jbaileyh/geogrid/blob/master/inst/extdata/london_LA.json

# Set arguments for plot
par(mfrow = c(2,3),mar = c(0,2,0))

# Hexagonal grid with 6 seeds
for (i in 1:3) {
  grid_hexagon <- calculate_grid(shape = df,learning_rate = 0.05,grid_type = "hexagonal",seed = i)
  plot(grid_hexagon,main = paste("Seed",i,sep = " "))
}

# Square grid
for (i in 1:3) {
  grid_square <- calculate_grid(shape = df,grid_type = "regular",seed = i)
  sp::plot(grid_square,sep = " "))
}

# Get a SpatialDataFrame from our desired grid
tmp <- calculate_grid(shape = df,seed = 3)
df_hex <- assign_polygons(df,tmp)

# And export to TopoJSON
topojson_write(df_hex,object_name = "local_authorities",file = "output/london_hex.json")

有关如何解决此问题的任何建议？另外，我对了解生成特定输入文件的十六进制制图的其他方法感兴趣。

参考：https://github.com/jbaileyh/geogrid

解决方法

您可以将SpatialPolygonsDataFrame转换为sf，然后使用st_write写入GeoJSON文件：

library(sf)                                                                                                                               
df_hex = st_as_sf(df_hex)                                                                                                                 
st_write(df_hex,"df_hex.geojson") 

这是QGIS中的结果：