## mapping continuous data
data(gridExData,envir=environment(),package="rworldmap")
gridExData <- get("gridExData")
mapGriddedData(gridExData)
## reclassing continuous data to categorical & mapping
data(gridExData,envir=environment(),package="rworldmap")
#find quartile breaks
cutVector <- quantile(gridExData@data[,1],na.rm=TRUE)
#classify the data to a factor
gridExData@data$categories <- cut( gridExData@data[,1]
, cutVector, include.lowest=TRUE)
#rename the categories
levels(gridExData@data$categories) <- c('low', 'med', 'high', 'vhigh')
#mapping
mapGriddedData( gridExData, nameColumnToPlot= 'categories'
, catMethod='categorical')Run the code above in your browser using DataLab