r - 将 data.frame 转换为 SpatialPolygonsDataFrame

Question

以下是用于重现目的的数据:

  structure(list(countyfp10 = c(1, 1, 1, 1, 3, 3, 3, 3, 5, 5, 5, 
5, 7, 7, 7, 7), id = c(7417, 7418, 7419, 7420, 7421, 7422, 7423, 
7424, 7425, 7426, 7427, 7428, 7429, 7430, 7431, 7432), lat = c(39.4797245, 
39.5544678, 39.4681687, 39.199806, 39.4017623, 39.3093943, 39.4272021, 
39.5618129, 39.7934997, 39.4835134, 39.4989196, 39.4819145, 39.4727694, 
39.4675515, 39.4693146, 39.4644503), long = c(-118.7908571, -118.8095638, 
-118.8195712, -118.5429041, -118.754186, -118.8861865, -118.9729817, 
-117.9418517, -118.9516281, -118.8487913, -119.0205114, -118.7695846, 
-118.7938896, -118.76011, -118.7778707, -118.7902103)), class = c("spec_tbl_df", 
"tbl_df", "tbl", "data.frame"), row.names = c(NA, -16L), spec = structure(list(
    cols = list(countyfp10 = structure(list(), class = c("collector_double", 
    "collector")), id = structure(list(), class = c("collector_double", 
    "collector")), lat = structure(list(), class = c("collector_double", 
    "collector")), long = structure(list(), class = c("collector_double", 
    "collector"))), default = structure(list(), class = c("collector_guess", 
    "collector")), skip = 1), class = "col_spec"))

这是当前存储为 data.frame但我想把它转换成 SpatialPolygonsDataFrame .最好的方法是什么？

Answer 1

我开发了 sfheaders图书馆为此目的。

devtools::install_github("dcooley/sfheaders")
library(sfheaders)

sf <- sfheaders::sf_polygon(
    obj = df
    , x = "long"
    , y = "lat"
    , polygon_id = "countyfp10"
)

并在传单中展示它的工作原理(其他 plotting libraries 可用；))

library(leaflet)
leaflet() %>%
    addTiles() %>%
    addPolygons(data = sf)