RG#100: Trellis map plot with heatmap colors

require(maps)
library(mapproj)

worldmap <- map('world', plot = FALSE, fill = FALSE,  projection = "azequalarea")
country = worldmap$names
set.seed(1234)
var.2010 = rnorm (length (country), 20, 10)
var.2011 = var.2010*1.1 + rnorm (length (country), 0, 1)
var.2012 = var.2011*0.98 + rnorm (length (country), 0, 4)
var.2013 = var.2011*0.98 + rnorm (length (country), 0, 30)
worldt <- data.frame (country, var.2010, var.2011, var.2012, var.2013)

mapplot(country ~ var.2011, worldt, map = map("world",     plot = FALSE, fill = TRUE))

mapplot(country ~ var.2010 + var.2011 + var.2012 + var.2013, data = worldt, map = map("world",     plot = FALSE, fill = TRUE))

# trellis plot for country maps not available in maps package:

 require(maptools)
# get the map; may need sometime to be loaded 
con <- url("http://gadm.org/data/rda/NPL_adm3.RData")
print(load(con))
close(con)

# from your data file working directory 
## load ("NPL_adm3.RData")

# data 
districts = gadm$NAME_3
set.seed(1234)
var1 <- rnorm (length (districts), 100, 30)
var2 <- rnorm (length (districts), 100, 30)
 myd <- data.frame (districts, var1, var2)    

# US county level map 

uscountymap <- map('county', plot = FALSE, fill = FALSE,  projection = "azequalarea")
county = uscountymap$names
set.seed(1234)
var.2010 = rnorm (length (county), 50, 10)
var.2011 = var.2010*1.1 + rnorm (length (county), 0, 5)
var.2012 = var.2011*0.98 + rnorm (length (county), 0, 10)
var.2013 = var.2011*1.2 + rnorm (length (county), 0, 15)
uscounty <- data.frame (county, var.2010, var.2011, var.2012, var.2013)

mapplot(county ~ var.2010 + var.2011 + var.2012 + var.2013, data = uscounty, map = map("county",    plot = FALSE, fill = TRUE))

# US state level map 
usstmap <- map('state', plot = FALSE, fill = FALSE,  projection = "azequalarea")
state = usstmap$names
set.seed(1234)
var.2010 = rnorm (length (state), 50, 10)
var.2011 = var.2010*1.1 + rnorm (length (state), 0, 5)
var.2012 = var.2011*0.98 + rnorm (length (state), 0, 10)
var.2013 = var.2011*1.2 + rnorm (length (state), 0, 15)
usst <- data.frame (county, var.2010, var.2011, var.2012, var.2013)

mapplot(state ~ var.2010 + var.2011 + var.2012 + var.2013, data = usst, map = map("state",    plot = FALSE, fill = TRUE), colramp = colorRampPalette(c("green", "purple")))