问用日期变量创建世界地图

EN

#Your data
formdate <- read.table(text="
ISO3\tCountry\tFormation Date
DZA\tAlgeria\t07-03-1962
AGO\tAngola\t11-11-1975
BWA\tBotswana\t09-30-1966
CMR\tCameroon\t01-01-1960
BGD\tBangladesh\t03-26-1971
IND\tIndia\t08-15-1947
ISR\tIsrael\t05-14-1948
LOS\tLaos\t10-22-1953
MYS\tMalaysia\t09-16-1963
SGP\tSingapore\t08-09-1965"
,sep="\t",header=TRUE)

#just using year as a first step
formdate$Formation.Year<-year(formdate$Formation.Date)

#sPDF <- joinCountryData2Map( formdate, joinCode="ISO3", nameJoinColumn="ISO3")
#joining by country name works better because of incorrect ISO3 code for Laos in the data
sPDF <- joinCountryData2Map( formdate, joinCode="NAME", nameJoinColumn="Country")

#Using defaults, change catMethod, numCats & colourPalette to change map appearance
mapCountryData(sPDF, nameColumnToPlot="Formation.Year")

#I've used these breaks that work with your sample data, 
#simply cahnge to work with full dataset
yearBreak1 <- 1960
yearBreak2 <- 1970

oldPar <- par(mar=c(0.7, 0, 0, 0)) #set margins for subplots top,bottom,left,right
#use layout to set up 3 panels
nPanels <- layout( cbind(c(0,1:3))
                   , heights=c(lcm(0.5),c(1,1,1))
                   , respect=F )

#add a constant column to allow plotting all countries the same colour 
formdate$constant <- 1

#subet data by yearBreaks
dF1 <- formdate[ formdate$Formation.Year <= yearBreak1, ]  
dF2 <- formdate[ formdate$Formation.Year > yearBreak1 & formdate$Formation.Year <= yearBreak2, ]                          
dF3 <- formdate[ formdate$Formation.Year > yearBreak2, ]                          

#join to a map
sPDF1 <- joinCountryData2Map( dF1, joinCode="NAME", nameJoinColumn="Country")
sPDF2 <- joinCountryData2Map( dF2, joinCode="NAME", nameJoinColumn="Country")
sPDF3 <- joinCountryData2Map( dF3, joinCode="NAME", nameJoinColumn="Country")

#plot & add titles
mapCountryData(sPDF1, nameColumnToPlot="constant", catMethod='categorical', addLegend=FALSE, mapTitle="" )
mtext(paste("<=",yearBreak1))
mapCountryData(sPDF2, nameColumnToPlot="constant", catMethod='categorical', addLegend=FALSE, mapTitle="" )
mtext(paste(">",yearBreak1,"& <=",yearBreak1))
mapCountryData(sPDF3, nameColumnToPlot="constant", catMethod='categorical', addLegend=FALSE, mapTitle="" )     
mtext(paste(">",yearBreak2))

# First changing the class of the two columns we're going to use:
formdate$Formation.Date<-as.Date(formdate$Formation.Date, "%m-%d-%Y")
formdate$ISO3<-as.character(formdate$ISO3)
formdate$ISO3[8]<-"LAO" #Laos'ISO3 code is "LAO" and not "LOS" in the wrld_simpl data
# Make regular temporal interval
intval <- cut(formdate$Formation.Date, 
              breaks = seq(min(formdate$Formation.Date),max(formdate$Formation.Date),length=5), 
              right=TRUE, include.lowest=TRUE) # So that the intervals include the lowest date and the highest
# Make these values correspond with their polygons
library(maptools)
data(wrld_simpl)
f <- rep(NA,nrow(wrld_simpl@data))
f[sapply(formdate$ISO3,function(x)which(wrld_simpl$ISO3==x))] <- intval
# Plot
plot(wrld_simpl, col=(1:6)[f])

#This time you can define your breakpoints before hand (don't forget to include a minimum age and a maximum age)
d <- c("1900/01/01","1945/01/01","1965/01/01","2020/01/01")
intval <- cut(formdate$Formation.Date, 
                  breaks = as.Date(d))
f <- rep(0,nrow(wrld_simpl@data))
f[sapply(formdate$ISO3,function(x)which(wrld_simpl$ISO3==x))] <- intval

par(mfcol=c(3,1)) #Here, three vertical panels
for(i in 1:3){
   par(mar=c(0,0,0,0))
   plot(wrld_simpl) #First plot the whole world
   if(any(f==i)){
       plot(wrld_simpl[f==i,],add=TRUE,col="red") #Then the countries that belong to the proper category
       }
   }