subset_county_polygons: subset_county_polygons

In USGS-R/AWUDS: wateRuse data analysis functions

Description

Returns county polygons from: Siczewicz, Peter. U.S. Historical Counties (Generalized .001 deg) on the basis of year of interest Dataset is subset on basis of area of interest

Usage

subset_county_polygons(year, area.column, areas)

Arguments

year	int, the year of interest to be mapped (defines historical basis for counties)
area.column	chr, defines which column to use to specify area
areas	chr, vector of codes indicating HUCs, counties, states, regions, aquifers, etc.

Value

hc.sub dataframe, a subset of county polygon data

Examples

areas <- "Delaware" # 3 counties present day
area.column <- "STATE_TERR"
year <- 2010 
hc.sub <- subset_county_polygons(year, area.column, areas)
hc.sub$NAME

areas <- "Maine" # 16 counties present day
area.column <- "STATE_TERR"
year <- 2010 
hc.sub <- subset_county_polygons(year, area.column, areas)
hc.sub$NAME
year <- 1850 # Maine had 13 counties in 1850; Delaware 3
hc.sub <- subset_county_polygons(year, area.column, areas)
hc.sub$NAME

USGS-R/AWUDS documentation built on May 9, 2019, 6:05 p.m.