在R中将SpatialPolygonsDataFrame导出为geojson或topojson

Question

我正在尝试将伦敦地方当局的geojson转换为十六进制地图，其中每个六边形代表一个地方当局。它在R中工作，但当我尝试将生成的六边形网格导出为geojson或topojson时，我得到了以下错误：

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

这是代码。我使用geogrid生成网格，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, 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, main = paste("Seed", i, sep = " "))
}

# Get a SpatialDataFrame from our desired grid
tmp <- calculate_grid(shape = df, grid_type = "hexagonal", 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")

关于如何解决这个问题，有什么建议吗？此外，我很有兴趣听到其他方法来生成十六进制图表，给出一个特定的输入文件。

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

Answer 1

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") 

以下是QGIS中的结果：

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