plotpoly: Plots polygons defined by the coverages.

In RArcInfo: Functions to import data from Arc/Info V7.x binary coverages

Description

This function is capable of plotting polygons, referenced by its id number. These can be filled with colors acording to a given variate.

Usage

plotpoly(arc,bnd,pal,index=NULL,col, border=NULL,xratio=1, yratio=1,...)

Arguments

arc	The data returned by a call to get.arcdata
bnd	The data returned by a call to get.bnddata
pal	The data returned by a call to get.paldata
index	IDs of the polygon to be plotted. If it is 'NULL' then all the polygons are plotted.
col	Colors to be used when filling the polygons
border	Colors used for the lines of the polygons. If it's not set, it is set to the value of 'col'.
xratio	Controls x-axis ratio. It can take any value from 0 to 1.
yratio	Controls x-axis ratio. It can take any value from 0 to 1.
...	Options to be passed to a call to the function plot when creating the display (i. e., window or file).

Value

Thins function returns nothing, but plots a nice map. :-D

Examples

#This example is the same as the one provided under the test directory

#1.- Create temporary directory (if needed)
#1.- Extract the E00 file form a ZIP file
#2.- Create an Arc/Info binary coverage
#3.- Create the map

#get current working directory
cwd<-getwd()
#Create tmp directory.
tmpdir<-tempdir()


datadir<-system.file("exampleData",package="RArcInfo")
setwd(datadir)
file.copy(c("valencia.zip", "data_valencia.csv"), tmpdir, overwrite = TRUE)

setwd(tmpdir)

#Convert E00 file to a binary covertage to be imported into R

#Comment this line if the file valencia.e00 already exists
unzip(zipfile="valencia.zip", file="valencia.e00")

#Comments this lines if the binary coverage already exists
library(RArcInfo)
e00toavc("valencia.e00", "valencia")


#Read map data
arcsmuni<-get.arcdata(".", "valencia")
palmuni<-get.paldata(".", "valencia")
bnd.muni<-get.bnddata("info/", "VALENCIA.BND")
patmuni<-get.tabledata("./info", "VALENCIA.PAT")

#Number of polygons
nmuni<-length(palmuni[[1]][[1]])

municipios<-data.frame(1:nmuni, patmuni$"VALENCIA-ID")
names(municipios)<-c("INDEX", "CODMUNICI")


#Datafiles to be used

unemp<-read.table(file="data_valencia.csv", sep=";", 
	dec = ",",skip=1)

unemp<-unemp[,c(1,3)]
names(unemp)<-c("CODMUNICI", "UNEMP")

breaks<-quantile(unemp[,2], c(0,  .025,.2, .8, .975, 1))

unemp<-cbind(unemp, CAT=as.ordered(cut(unemp[,2], breaks, include.lowest = TRUE) ))


library(RColorBrewer)

#Colors to be used in maps
#colors<-brewer.pal(5, "Oranges")
colors<-brewer.pal(5, "Greens")

ldata<-merge(unemp, municipios, by.x="CODMUNICI", by.y="CODMUNICI")


#Valencia
idx<-(ldata$"CODMUNICI">=46000)
bnd.muni<-c(626679.9, 4250000, 760000, 4460000)


p<-par()
pin<-1.5*p$pin
main<-"Rate of unemployment"

plotpoly(arc=arcsmuni, pal=palmuni, bnd=bnd.muni,
	index=ldata$INDEX[idx], col=colors[ldata$CAT][idx],
	xlab="", ylab="", main=main,
	xaxt="n", yaxt="n", bty="n")

#Set legend
l<-levels(unemp$CAT)
l[1]<-"[0.00,1.26]"
legend(700000, 4460000, fill=colors, 
legend=l, bty="n", cex=1)

setwd(cwd)

Example output

Loading required package: RColorBrewer
[1] TRUE TRUE
NULL
Number of ARCS:1074
Number of POLYGONS:396

RArcInfo documentation built on May 1, 2019, 10:26 p.m.