Hi guys
i need some help to build choropleth.
Basically i am trying to colour regions on the map by population.
I possess the shape file of the country, and also the population data,
however, i am having trouble to create the plot, below is my code:
population=read.csv("nz2.csv")
population
names(population)
nz=readShapeSpatial((sprintf('nz-geodetic-marks',tmp_dir)))
nz$land_distr
mapnames = nz$land_distr
mapnamesnew=as.character(mapnames)
popnames =as.character(mapnamesnew)
pop =population$People
pop2=as.numeric(pop)
popdich = ifelse(pop2 < 100000, "red", "blue")
popnames.lower = tolower(popnames)
cols=popdich[match(mapnames,popnames.lower)]
plot(nz,fill=TRUE,col=cols,proj="GCS_NZGD_2000")
thanks in advance for any assistance
Kind regards
Iverson
--
View this message in context:
http://r.789695.n4.nabble.com/R-help-using-R-to-build-choropleth-tp4634686.html
Sent from the R help mailing list archive at Nabble.com.
Hello, You can find some hints there: http://geography.uoregon.edu/geogr/topics/index.html Regards Le 12/06/28 14:26, iverson a ?crit :> Hi guys > > i need some help to build choropleth. > > Basically i am trying to colour regions on the map by population. > > I possess the shape file of the country, and also the population data, > however, i am having trouble to create the plot, below is my code: > > > > population=read.csv("nz2.csv") > population > names(population) > > nz=readShapeSpatial((sprintf('nz-geodetic-marks',tmp_dir))) > > nz$land_distr > > mapnames = nz$land_distr > > mapnamesnew=as.character(mapnames) > > popnames =as.character(mapnamesnew) > pop =population$People > > pop2=as.numeric(pop) > > popdich = ifelse(pop2 < 100000, "red", "blue") > popnames.lower = tolower(popnames) > > cols=popdich[match(mapnames,popnames.lower)] > > plot(nz,fill=TRUE,col=cols,proj="GCS_NZGD_2000") > > > > > thanks in advance for any assistance > > Kind regards > > Iverson > > > > -- > View this message in context: http://r.789695.n4.nabble.com/R-help-using-R-to-build-choropleth-tp4634686.html > Sent from the R help mailing list archive at Nabble.com. > > ______________________________________________ > R-help at r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. >
On 06/28/2012 03:26 PM, iverson wrote:> Hi guys > > i need some help to build choropleth. > > Basically i am trying to colour regions on the map by population. > > I possess the shape file of the country, and also the population data, > however, i am having trouble to create the plot, below is my code: > > > > population=read.csv("nz2.csv") > population > names(population) > > nz=readShapeSpatial((sprintf('nz-geodetic-marks',tmp_dir))) > > nz$land_distr > > mapnames = nz$land_distr > > mapnamesnew=as.character(mapnames) > > popnames =as.character(mapnamesnew) > pop =population$People > > pop2=as.numeric(pop) > > popdich = ifelse(pop2< 100000, "red", "blue") > popnames.lower = tolower(popnames) > > cols=popdich[match(mapnames,popnames.lower)] > > plot(nz,fill=TRUE,col=cols,proj="GCS_NZGD_2000") >Hi Iverson, Here is some code that I have used to draw a choropleth map of NSW where the colors represent the average Index of Relative Social Disadvantage for Statistical Local Areas in New South Wales. I've cut out the bits that map the locations of low speed vehicle runovers as you won't need that code. # load the RGDAL package require(rgdal) # read in the SLA boundaries for Australia SLAmap<-readOGR(".","SLA10aAust") # pick out the bits in NSW NSWmap<-SLAmap[1:199,] # read in the SEIFA (including IRSD) values AU_SEIFA<-read.csv("AU_SEIFA_SLA_2006.csv") require(plotrix) # generate the colors for the IRSD scores NSW_SEIFAcol<-color.scale(AU_SEIFA$SEIFA1dec[1:199], c(1,0.9,0.8,0.8),c(0.8,0.9,0.9,0.8),c(0.8,0.8,0.9,1),xrange=c(0,10)) # open the graphics device png("lsvro_NSW_96-10.png",width=700,height=700) par(mar=c(4,0,3,1)) # plot the map with the colors plot(NSWmap,xlim=c(140,max(lsvro$longitude,na.rm=TRUE)), col=NSW_SEIFAcol) legend_values<-c(0:10) # generate the colors for the legend SEIFAlegendcol<-color.scale(legend_values, c(1,0.9,0.8,0.8),c(0.8,0.9,0.9,0.8),c(0.8,0.8,0.9,1)) # stick a legend on the side color.legend(151.8,-37.5,152.3,-34.5,as.character(legend_values),SEIFAlegendcol, align="rb",gradient="y") title(main="Low speed vehicle run overs NSW - 1996-2010") par(xpd=TRUE) # put a title on the color legend text(151.8,-34.3,"SEIFA decile",adj=0) par(xpd=FALSE) dev.off() Jim