The data comes from the American Community Survey (ACS). The variables are: total population, percent White not Hispanic, Percent Black or African American not Hispanic, percent Asian not Hispanic, percent Hispanic all races, per-capita income, median rent and median age.
get_tract_demographics(state_name, county_fips = NULL, endyear = 2013, span = 5)
The name of the state. See ?state.regions for proper spelling and capitalization.
An optional vector of county fips codes within the state. Useful to set because getting data on all tracts can be slow.
The end year for the survey
The span of the survey
The choroplethr guide to Census data: http://www.arilamstein.com/open-source/choroplethr/mapping-us-census-data/
A list of all ACS Surveys: http://factfinder.census.gov/faces/affhelp/jsf/pages/metadata.xhtml?lang=en&type=survey&id=survey.en.ACS_ACS