RcensusPkg (version 0.1.5)

tiger_zctas_sf: tiger_zctas_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.

Usage

tiger_zctas_sf(
  output_dir = tempdir(),
  delete_files = TRUE,
  vintage = 2020,
  general = FALSE,
  sf_info = FALSE,
  do_progress = FALSE,
  datafile = NULL,
  datafile_key = NULL,
  sf_key = NULL,
  express = NULL
)

Value

A data frame object of class sf

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 county geometries.

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.

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.

express

A logical expression object used to filter the resultant simple feature dataframe. For example, one of the columns of the resultant simple feature dataframe is "STATEFP". If you wanted to return just the geometries for Florida (which has a fips code of "12"), then you assign 'express' equal to: expression(STATEFP == "12"). The expression will be evaluated and only the geometries for Florida will be returned.

Details

Returns simple feature (sf) shapefile Zip Code Tabulation Areas(ZCTA) shapefile of the entire US.

Examples

if (FALSE) {
  # Beware that downloading and processing Zip Code Tabulation Areas(ZCTA)
  #   shapefiles of the entire US can be time consuming
  library(downloader)
  library(sf)
  library(data.table)
  library(withr)
  library(RcensusPkg)

  # Get the sf geometries for the Zip Code Tabulation Area in the county of
  #   Middlesex, MA near Boston
  # 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)
  }

  # Define the codes of interest in a dataframe
  mun_zcta_df <- data.frame(
    name = c(
      "Carlisle", "Concord", "Bedford",
      "Lexington", "Lexington", "Lincoln",
      "Lincoln", "Sudbury", "Wayland",
      "Weston","Waltham"
    ),
    zcta = c(
      "01741","01742","01730",
      "02420","02421","01773",
      "01731","01776","01778",
      "02493","02451"
    )
  )

  # Define an expression to filter the downloaded shapefile
  express <- expression(ZCTA5CE20 %in% mun_zcta_df$zcta)

  # Get the sf geometries
  mun_zcta_sf <- RcensusPkg::tiger_zctas_sf(
    vintage = 2020,
    general = TRUE,
    do_progress = TRUE,
    express = express,
    output_dir = output_dir,
    delete_files = FALSE
  )
}