r tidycensus download all block groups

问题:

I am looking to automate the process of downloading Census data from all block groups from the US using the tidycensus package. There is instructions from the developer to download all tracts within the US, however, block groups cannot be accessed using the same method.

Here is my current code that does not work

library(tidyverse)
library(tidycensus)
census_api_key("key here")

# create lists of state and county codes

data("fips_codes")
temp <- data.frame(state = as.character(fips_codes$state_code),
                   county = fips_codes$county_code,
                   stringsAsFactors = F)
temp <- aggregate(county~state, temp, c)
state <- temp$state
coun <- temp$county

# use map2_df to loop through the files, similar to the "tract" data pull

home <- map2_df(state, coun, function(x,y) {
get_acs(geography = "block group", variables = "B25038_001", #random var
state = x,county = y)
  })

The resulting error is

No encoding supplied: defaulting to UTF-8.
Error: parse error: premature EOF

                     (right here) ------^

A similar approach to convert the counties within each state into a list also does not work

temp <- aggregate(county~state, temp, c)
state <- temp$state
coun <- temp$county

df<- map2_df(state, coun, function(x,y) {
    get_acs(geography = "block group", variables = "B25038_001", 
            state = x,county = y)
  })

Error: Result 1 is not a length 1 atomic vector is returned.

Does anyone have an understanding of how this could be completed? More than likely I am not using functions properly or syntax, and I am also not very good with loops. Any help would be appreciated.

回答1:

Try this package: totalcensus at https://github.com/GL-Li/totalcensus. It downloads census data files to your own computer and extracts any data from these files. After set up folders and path, run the code below if you want all block group data in 2015 ACS 5-year survey.

library(totalcensus)

# download the 2015 ACS 5-year survey data, which is about 50 GB.
download_census("acs5year", 2015)

# read block group data of variable B25038_001 from all states plus DC
block_groups <- read_acs5year(
    year = 2015,
    states = states_DC,
    table_contents = "B25038_001",
    summary_level = "block group"
)

The extracted data of 217739 block groups of all states and DC:

    #                       GEOID       lon      lat state population B25038_001 GEOCOMP SUMLEV                                                              NAME
    #      1: 15000US020130001001 -164.1232 54.80448    AK        982         91     all    150     Block Group 1, Census Tract 1, Aleutians East Borough, Alaska
    #      2: 15000US020130001002 -161.1786 55.60224    AK       1116        247     all    150     Block Group 2, Census Tract 1, Aleutians East Borough, Alaska
    #      3: 15000US020130001003 -160.0655 55.13399    AK       1206        352     all    150     Block Group 3, Census Tract 1, Aleutians East Borough, Alaska
    #      4: 15000US020160001001  178.3388 51.95945    AK       1065        264     all    150 Block Group 1, Census Tract 1, Aleutians West Census Area, Alaska
    #      5: 15000US020160002001 -166.8899 53.85881    AK       2038        380     all    150 Block Group 1, Census Tract 2, Aleutians West Census Area, Alaska
    # ---                                                                                                                                                    
    # 217735: 15000US560459511001 -104.7889 43.99520    WY       1392        651     all    150          Block Group 1, Census Tract 9511, Weston County, Wyoming
    # 217736: 15000US560459511002 -104.4785 43.76853    WY       2050        742     all    150          Block Group 2, Census Tract 9511, Weston County, Wyoming
    # 217737: 15000US560459513001 -104.2575 43.88160    WY       1291        520     all    150          Block Group 1, Census Tract 9513, Weston County, Wyoming
    # 217738: 15000US560459513002 -104.1807 43.85406    WY       1046        526     all    150          Block Group 2, Census Tract 9513, Weston County, Wyoming
    # 217739: 15000US560459513003 -104.2601 43.84355    WY       1373        547     all    150          Block Group 3, Census Tract 9513, Weston County, Wyoming

回答2:

The solution was provided by the author of tidycensus (Kyle Walker), and is as follows:

Unfortunately this just doesn't work at the moment. If it did work, your code would need to identify the counties within each state within a function evaluated by map_df and then stitch together the dataset county-by-county, and state-by-state. The issue is that block group data is only available by county, so you'd need to walk through all 3000+ counties in the US in turn. If it did work, a successful call would look like this:

library(tigris)
library(tidyverse)
library(tidycensus)
library(sf)

ctys <- counties(cb = TRUE)

state_codes <- unique(fips_codes$state_code)[1:51]

bgs <- map_df(state_codes, function(state_code) {
  state <- filter(ctys, STATEFP == state_code)
  county_codes <- state$COUNTYFP
  get_acs(geography = "block group", variables = "B25038_001",
          state = state_code, county = county_codes)
})

The issue is that while I have internal logic to allow for multi-state calls, or multi-county calls within a state, tidycensus can't yet handle multi-state and multi-county calls simultaneously.