Draws a choropleth map given a spatialPolygons object, a variable and a shading scheme.
Usage
choropleth(sp, v, shading = auto.shading(v), ...)
Arguments
sp
A spatialPolygons or spatialPolygonsDataFrame object.
v
The variaqble to be mapped. Must have the same number of elements as s has polygons.
shading
A shading scheme created by shading or auto.shading.
...
Additional parameters to be passed on to the plot method for sp.
Details
The function returns no value, but draws a choropleth map on the current graphics device as a side effect.
Value
None (see above).
Author(s)
Chris Brunsdon
See Also
choro.legend, auto.shading, shading.
Examples
# Read in map data and compute a rate for mapping
sids <- readShapePoly(system.file("shapes/sids.shp", package="maptools")[1],
proj4string=CRS("+proj=longlat +ellps=clrk66"))
sids.rate=10000*sids$SID74/sids$BIR74
# Create the shading scheme, plot a choropleth map
shades = auto.shading(sids.rate,cols=brewer.pal(5,'Blues'))
choropleth(sids,sids.rate,shades)
Results
R version 3.3.1 (2016-06-21) -- "Bug in Your Hair"
Copyright (C) 2016 The R Foundation for Statistical Computing
Platform: x86_64-pc-linux-gnu (64-bit)
R is free software and comes with ABSOLUTELY NO WARRANTY.
You are welcome to redistribute it under certain conditions.
Type 'license()' or 'licence()' for distribution details.
R is a collaborative project with many contributors.
Type 'contributors()' for more information and
'citation()' on how to cite R or R packages in publications.
Type 'demo()' for some demos, 'help()' for on-line help, or
'help.start()' for an HTML browser interface to help.
Type 'q()' to quit R.
> library(GISTools)
Loading required package: maptools
Loading required package: sp
Checking rgeos availability: TRUE
Loading required package: RColorBrewer
Loading required package: MASS
Loading required package: rgeos
rgeos version: 0.3-19, (SVN revision 524)
GEOS runtime version: 3.5.0-CAPI-1.9.0 r4084
Linking to sp version: 1.2-3
Polygon checking: TRUE
> png(filename="/home/ddbj/snapshot/RGM3/R_CC/result/GISTools/choropleth.Rd_%03d_medium.png", width=480, height=480)
> ### Name: choropleth
> ### Title: choropleth
> ### Aliases: choropleth
>
> ### ** Examples
>
> # Read in map data and compute a rate for mapping
> sids <- readShapePoly(system.file("shapes/sids.shp", package="maptools")[1],
+ proj4string=CRS("+proj=longlat +ellps=clrk66"))
> sids.rate=10000*sids$SID74/sids$BIR74
> # Create the shading scheme, plot a choropleth map
> shades = auto.shading(sids.rate,cols=brewer.pal(5,'Blues'))
> choropleth(sids,sids.rate,shades)
>
>
>
>
>
> dev.off()
null device
1
>