I am new to R and working with census data and I am trying to build a csv file that can be passed to another team that shows the lat/long outline of census blocks.

With this I can get to 3 specific census blocks in Florida.

FL_blocks <- blocks("FL", year = 2010, )
FL_blocks_Alachua <- filter(FL_blocks, COUNTYFP == "001")
NTIA_FL_CB <- FL_blocks_Alachua %>%
  filter(FL_blocks_Alachua$GEOID10 %in% c ("120010019071008", "120010019071007", "120010019071009"))

Now I would like to make a table that just shows the lat/long and the corresponding census block that lat/long is associated with. This will give me the list of the lat/long for each census block and I can plot them with the polygon of the census block, but for me to pass this to a team unfamiliar with R, I need the csv data output.

NTIA_FL_CB_Shape_xy <- as.data.frame(st_coordinates(NTIA_FL_CB$geometry))
NTIA_FL_CB_Shape_xy <- NTIA_FL_CB_Shape_xy %>%
    rename( Longitude = X, Latitude = Y) %>%
    select(Latitude,Longitude )

# save lat/long as csv
st_write(NTIA_FL_CB_Shape_xy, "fl_3cb_ntia_latlong.csv", coords = TRUE)

# plot the 3 census blocks with the outline of the shapefiles marked as green circles
leaflet(NTIA_FL_CB) %>%
  addTiles() %>%
  addPolygons(popup = ~GEOID10) %>%
  addCircleMarkers(data = NTIA_FL_CB_Shape_xy, color = "green")

This image shows what I was thinking, If I could pass the lat/longs outlining each census block the team that uses my csv file output should be able to load that into their GIS software to overlay.

CodePudding user response：

The trick is to cast to point, then export. Or, if your team is using GIS software, you could write your multipolygon to a shapefile?

library(sf)

nc <- st_read(system.file("shape/nc.shp", package = "sf"), quiet = TRUE)
nc_pt <- st_cast(nc, "POINT")
st_write(nc_pt, "nc_pt.csv", layer_options="GEOMETRY=AS_XY")
# st_write(nc, "nc.shp")

https://gis.stackexchange.com/questions/294921/convert-shapefile-into-lat-long-points-and-export-it-as-csv-in-r