R/census_geocoding.r

In rwebsterav/rarsons: r implementation of parson, and other things i find useful

check <- function(type, value){
	if(value==""){
		return("")
	}
	else(
		return(paste(type
															,"="
															,gsub(" ", "+", value)
															, "&"
															,sep="")
									)
		)
}


#' currently throwing an ssl error
#' @export
census_geocoder <- function(address,zip,city,state){
	
	addr <- check("street",address)
	zip <- check("zip",zip)
	city <- check("city",city)
	state <- check("state",state)
	
	string <-  paste("https://geocoding.geo.census.gov/geocoder/geographies/address?"
																		,addr
																		,city
																		,zip
																		,state
																		,"benchmark=4&vintage=4&format=json"
																		,sep="")
	
	options(RCurlOptions = list(cainfo = system.file("CurlSSL", "cacert.pem", package = "RCurl")))
	
	print(paste("Geocoding ",string,sep=""))
	json_file <- jsonlite::fromJSON(
		RCurl::getURL(string)
		)
	
	if(length(json_file$result$addressMatches$coordinates)>0){
		if(is.null(json_file$result$addressMatches$coordinates$x[1])==TRUE){
			print("no result")
			return(data.frame(
				address=""
				,lat = ""
				,lon= ""
				,tract = ""
				,block = "")
				)
			
		} else{
			return(data.frame(
				address=as.character(data.frame(json_file$result$addressMatches$matchedAddress)[1,])
				,lat = as.character(json_file$result$addressMatches$coordinates$y[1])
				,lon= as.character(json_file$result$addressMatches$coordinates$x[1])
				,tract = data.frame(json_file$result$addressMatches$geographies$`Census Tracts`)$GEOID[1]
				,block = data.frame(json_file$result$addressMatches$geographies$`2010 Census Blocks`)[1,c("GEOID")]))
			
		}
	}
}