tiger_urban_area_sf {RcensusPkg}R Documentation

tiger_urban_area_sf

Description

This function performs three tasks:

  1. Download to an output directory a zip file from the TIGER/Line Shapefiles database.

  2. Unzip the zip file and locate the shape file of interest.

  3. Read and convert the shape file to a simple feature object.

The function returns geometries for the Census Bureau's defined "urban areas" across the entire US

Usage

tiger_urban_area_sf(
  output_dir = tempdir(),
  delete_files = TRUE,
  vintage = 2020,
  general = FALSE,
  resol = "500k",
  set_crs = NULL,
  transform_crs = NULL,
  sf_info = FALSE,
  do_progress = FALSE,
  shapefile = NULL,
  datafile = NULL,
  datafile_key = NULL,
  sf_key = "GEOID",
  check_na = FALSE
)

Arguments

output_dir

A full directory path where the shapefile and its associated files will be downloaded. The default is the directory defined by the value returned by tempdir().

delete_files

A logical which if TRUE will delete the shapefile and associated files in 'output_dir'. The default is TRUE.

vintage

A numeric that sets the vintage of interest. The default is 2020.

general

A logical which if TRUE will download a less detailed, more generalized version of the state geometries.

resol

If 'general' is TRUE, then the resolution to return. Acceptable values are strings "500k", "5m", "20m".

set_crs

A numeric or character string which if non-NULL calls sf::st_crs() to set the crs of the geometries and transforms them.

transform_crs

A numeric or character string which if non-NULL calls sf::st_transform() to perform a crs transform of the geometries. Note that the crs of the shapefile must not be NA.

sf_info

A logical which if TRUE displays info on the resulting simple feature object.

do_progress

A logical which if TRUE displays a progress bar during the download.

shapefile

A full file path to a shapefile folder with its unzipped files to be processed instead of downloading.

datafile

A dataframe containing data that should be joined with this function's resultant simple feature object.

datafile_key

The column name from 'datafile' dataframe used to key with the 'sf_key' column of the resultant simple feature dataframe.

sf_key

The column from the resultant dataframe used to key with the 'datafile' dataframe.

check_na

A logical which if TRUE will remove rows that have missing values for any of the columns. The default is to not check the columns for NA values.

Details

Returns simple feature(sf) of the Census Bureau's defined "urban area" boundary related geometric polygons, provided by the US Census Bureau's TIGER/Line Shapefiles database. See Simple Features for R for more information on simple features.

A more generalized, recognizable version of the CBSA geometries that has less download size is also available. For more information on cartographic boundary files see Cartographic Boundary File Description. These files are available for vintages greater than 2009 with resolution 1:500k, 1:5m, 1:20m meters. For descriptive information on CBSA see About.

The function returns the simple feature object which can easily be mapped (see RplotterPkg::create_sf_plot()) or joined with US Census Bureau demographic data. To help incorporate data files, this function has a 'datafile' parameter which will be joined with the resultant simple feature object. The only requirement is that a common "key" for joining exist between the data dataframe and the simple feature dataframe.

Value

A data frame object of class sf

Examples

library(downloader)
library(sf)
library(data.table)
library(withr)
library(RcensusPkg)

# Get the defined urban areas for 2019
# Define a temporary, self deleting output folder for the downloaded shapefiles
output_dir <- withr::local_tempdir()
if(!dir.exists(output_dir)){
  dir.create(output_dir)
}

us_urban_areas_sf <- RcensusPkg::tiger_urban_area_sf(
  output_dir = output_dir,
  vintage = 2019,
  general = TRUE,
  delete_files = FALSE
)


[Package RcensusPkg version 0.1.5 Index]