Character string or vector. Must be the actual name of the demographic variables attached to UScensus2010 objects. Default dem = " P0010001"
state
a character string, can either be the full name of a state (e.g. "oregon"), the abbreviation (e.g. "or"), or the FIPS code (e.g. "41")– note that if you are using the FIPS code you have to change statefips to TRUE. This variable is insensitive to case.
statefips
logical, by default statefips=FALSE, set to TRUE if using the state FIPS codes.
level
a character string, takes levels tract, blk, blkgrp, cdp, msa or county
msaname
logical (optional), if level="msa", allows the use of the verbose MSA placename (capitalized).
Value
An object of class matrix.
Warning
You must have the packages UScensus2010tract, UScensus2010blkgrp and UScensus2010blk installed to use levels "blkgrp" and "blk" respectively.
Zack W. Almquist (2010). US Census Spatial and Demographic Data in R: The UScensus2000 Suite of Packages. Journal of Statistical Software, 37(6), 1-31. http://www.jstatsoft.org/v37/i06/.