county_choropleth_acs: Create a US County choropleth from ACS data

Description

Creates a US County choropleth using the US Census' American Community Survey (ACS) data. Requires the acs package to be installed, and a Census API Key to be set with the acs's api.key.install function. Census API keys can be obtained at http://www.census.gov/developers/tos/key_request.html.

Usage

county_choropleth_acs(
  tableId,
  endyear = 2011,
  span = 5,
  num_colors = 7,
  state_zoom = NULL,
  county_zoom = NULL
)

Value

A choropleth.

Arguments

tableId: The id of an ACS table
endyear: The end year of the survey to use. See acs.fetch (?acs.fetch) and http://1.usa.gov/1geFSSj for details.
span: The span of time to use. See acs.fetch and http://1.usa.gov/1geFSSj for details.
num_colors: The number of colors on the map. A value of 1 will use a continuous scale. A value in [2, 9] will use that many colors.
state_zoom: An optional vector of states to zoom in on. Elements of this vector must exactly match the names of states as they appear in the "region" column of ?state.regions.
county_zoom: An optional vector of counties to zoom in on. Elements of this vector must exactly match the names of counties as they appear in the "region" column of ?county.regions.

References

Uses the acs package created by Ezra Haber Glenn.

Examples

Run this code

if (FALSE) {
# median income, all counties in US
county_choropleth_acs("B19301")

# continuous scale, zooing in on all counties in New York, New Jersey and Connecticut
county_choropleth_acs("B19301", num_colors=1, state_zoom=c("new york", "new jersey", "connecticut"))

# zooming in on the 5 counties (boroughs) that make up New York City
library(dplyr)
library(choroplethrMaps)
data(county.regions)

nyc_county_names=c("kings", "bronx", "new york", "queens", "richmond")
nyc_county_fips = county.regions %>%
  filter(state.name=="new york" & county.name %in% nyc_county_names) %>%
  select(region)
county_choropleth_acs("B19301", num_colors=1, county_zoom=nyc_county_fips$region)
}