R code to Generating map of US states with specific colors

Question

I am trying to generate the map of U.S. in which each state can have one of the following colors:

EScolors <- c(\"#7aad42\",\"#4a77bb\",\"#f7931e\",\"#d3dfbd\         


        

Answer 1

Using the base maps package can be a little tricky. The order and the naming of the states is not standard, several states have more than one region, i.e. Manhattan island in New York. A little manipulation is required to properly label/color the map.
In this solution, I created a dataframe statelist to hold the state names, islands and an index. Then merge this with your dataframe, state_info, and then plotted.

#function to split strings an return a dataframe
strtodf<-function (list){
  slist<-strsplit(list, ":")
  x<-sapply(slist, FUN= function(x) {x[1]})
  y<-sapply(slist, FUN= function(x) {x[2]})
  df<-data.frame(state=x, island=y, stringsAsFactors = FALSE)
  return(df)
}

#user defined coloring scheme
#    Example data for to test solution
colors<- c("#7aad42","#4a77bb","#f7931e","#d3dfbd","#787878")
region<-c("washington", "new york", "virginia", "pennsylvania", "ohio")
states_info<-data.frame(region, colors)
#    End of example data

#dataframe to hold state names for mapping purposes
library(maps)
maplist<-map("state", namesonly = TRUE, plot=FALSE)
statelist<-strtodf(maplist)  #convert to dataframe
statelist$row<-as.numeric(rownames(statelist))  #index column

#merge the data from and resort into proper order
statelist<-merge(statelist, states_info, by.x = "state", by.y="region", sort=FALSE, all.x=TRUE)
statelist<-statelist[order(statelist$row),]

#plot the map
maplist<-map("state", fill=TRUE, col=statelist$colors)

Answer 2

Let ggplot2 do the hard work for you:

library(ggplot2)

read.table(text="State.Code   region St_Abbr Num_Estab  colors
1          1   alabama      AL     13123 #f7931e
3          4   arizona      AZ     18053 #f7931e
4          5   arkansas      AR      9154 #4a77bb
5          6   california      CA    143937 #787878
6          8   colorado      CO     21033 #d3dfbd
7          9   connecticut      CT     17176 #f7931e", 
           stringsAsFactors=FALSE, header=TRUE, comment.char="") -> df

usa_map <- map_data("state")

gg <- ggplot()
gg <- gg + geom_map(data=usa_map, map=usa_map,
                    aes(long, lat, map_id=region),
                    color="#2b2b2b", size=0.15, fill=NA)
gg <- gg + geom_map(data=df, map=usa_map,
                    aes(fill=colors, map_id=region),
                    color="#2b2b2b", size=0.15)
gg <- gg + scale_color_identity()
gg <- gg + coord_map("polyconic")
gg <- gg + ggthemes::theme_map()
gg