How to visualize data on Maps by R?
Hi, everyone! I came back! After several days of study I found something that is super interesting in R: drawing maps.
There three ways of drawing maps:1. get you own map data. 2.get data from r maps and map data library. 3 use ggmap library.
Using your own data:
library(maps)
library(mapdata)
#install.packages("maptools")
library(maptools)
#install.packages("sp")
library(sp)
x=readShapeSpatial("/Users/leilei/Desktop/The Last Semester/ADA/china-province-border-data/bou2_4p.shp")
install.packages("gpclib")
gpclibPermit()
gpclibPermitStatus()
plot(x)
Using map library:
library(maps)
map("world", fill = TRUE, col = rainbow(200),
ylim = c(-60, 90), mar = c(0, 0, 0, 0))
title("world map")
What a colorful map!~
Using GGmap:
library(ggmap)
library(ggplot2)
geocode("Fordham University", output = "more")
output:
lon lat type loctype address
1 -73.8857 40.86204 university approximate fordham university, bronx, ny 10458, usa
north south east west postal_code country
1 40.86469 40.85781 -73.88066 -73.89047 10458 united states
administrative_area_level_2 administrative_area_level_1 locality street streetNo
1 bronx county new york <NA> <NA> NA
point_of_interest query
1 <NA> Fordham University
Also, you can draw gif by ggmap:
library(ggmap)
library(animation)
library(XML)
library(ggplot2)
webpage <-'http://www.ldeo.columbia.edu/cgi-bin/quake.cgi'
#download earthquake data from this website
tables <- readHTMLTable(webpage,stringsAsFactors = FALSE)
raw <- tables[[1]]
data <- raw[-1,c('V1','V3','V4')]
data$V3<-sub("\\D*$","",as.vector(as.matrix(data$V3)))
data$V4<-sub("\\D*$","",as.vector(as.matrix(data$V4)))
#using regular expression to change the location
names(data) <- c('date','lan','lon')
data$lan <- as.numeric(data$lan)
data$lon <- -as.numeric(data$lon)
data$date <- as.Date(data$date,"%Y-%m-%d")
#why did you do that?
ggmap(get_googlemap(location="united states", zoom=4,maptype='terrain'),extent='device')+
geom_point(data=data,aes(x=lon,y=lan),colour = 'red',alpha=0.7)+stat_density2d(aes(x=lon,y=lan,fill=..level..,alpha=..level..),
size=2,bins=4,data=data,geom='polygon')+theme(legend.position = "none")
plotfunc <- function(x) {
df <- subset(data,date <= x)
df$lan <- as.numeric(df$lan)
df$lon <- as.numeric(df$lon)
p <- ggmap(get_googlemap(location="united states", zoom=4,maptype='terrain'),extent='device')+
geom_point(data=df,aes(x=lon,y=lan),colour = 'red',alpha=0.7)
}
time <- sort(unique(data$date))
saveGIF(for( i in time) print(plotfunc(i)))
That's it.
Reference:
