将一个sf对象导出到多个shapefile

Question

我有一个很大的shapefile，需要按属性（分组值）将其拆分成几个。在ArcGIS中，此函数调用Split By Attribute，以Split By Attribute库为例，读取nc数据帧

sf

我想根据

library(tidyverse)
library(sf)

nc = st_read(system.file("shape/nc.shp", package="sf"))

nc

Simple feature collection with 100 features and 14 fields
geometry type:  MULTIPOLYGON
dimension:      XY
bbox:           xmin: -84.32385 ymin: 33.88199 xmax: -75.45698 ymax: 36.58965
epsg (SRID):    4267
proj4string:    +proj=longlat +datum=NAD27 +no_defs
First 10 features:
    AREA PERIMETER CNTY_ CNTY_ID        NAME  FIPS FIPSNO CRESS_ID
1  0.114     1.442  1825    1825        Ashe 37009  37009        5
2  0.061     1.231  1827    1827   Alleghany 37005  37005        3
3  0.143     1.630  1828    1828       Surry 37171  37171       86

变量将其分割为100个shapefile。所以我要像这样进入NAME，group_by和nest。

walk

这个漂亮的管道向我返回了以下错误：

错误：无法将

nc %>% 
  mutate(group = as.character(NAME)) %>% 
  group_by(group) %>%
  nest() %>% 
  mutate(data = map(data, ~st_as_sf(.x))) %>% 
  walk2(.x = data, .y = group,
       ~st_write(obj = .x,
                 dsn = paste0(.y,
                              ".shp")))

对象转换为函数

Answer 1

grouped_df/tbl_df/tbl/data.frame