library(rgdal)
library(ggplot2)
library(rgeos)
library(plyr)

#this data comes from http://www.gadm.org/country (download the Great Britain data set, and set path to the downloaded data's topmost directory)
shape.dir <- "C:\Users\Douglas\Desktop\estc_clean_analysis\geoanalysis\GBR_adm"

#the first parameter we pass to readOGR species the location of the shapefile we want to read in; layer indicates which shapefile in that dir we want to read in. Data via UK shapefile from http://www.gadm.org/country
uk.shp <- readOGR(shape.dir, layer = "GBR_adm2")

#read in csv with values by county
small_geo_data <- read.csv(file = "small_geo_sample.txt", header=TRUE, sep="t", na.string=0, strip.white=TRUE)

#fortify prepares the data for ggplot
uk.df <- fortify(uk.shp, region = "ID_2") # convert to data frame for ggplot

#now combine the values by id values in both dataframes
combined.df <- join(small_geo_data, uk.df, by="id")

#now build plot up layer by layer
ggp <- ggplot(data=combined.df, aes(x=long, y=lat, group=group))
ggp <- ggp + geom_polygon(aes(fill=value))         # draw polygons
ggp <- ggp + geom_path(color="grey", linestyle=2)  # draw boundaries
ggp <- ggp + coord_equal()
ggp <- ggp + scale_fill_gradient(low = "#ffffcc", high = "#ff4444",
                                 space = "Lab", na.value = "grey50",
                                 guide = "colourbar")
ggp <- ggp + labs(title="Plotting Values in Great Britain")
# render the map
print(ggp)