RgoogleMaps (version 1.4.2)

PlotPolysOnStaticMap: plots polygons on map

Description

This function plots/overlays polygons on a map. Typically, the polygons originate from a shapefile.

Usage

PlotPolysOnStaticMap(MyMap, polys, col, border = NULL, lwd = 0.25, 

    verbose = 0, add = TRUE, textInPolys = NULL, ...)

Arguments

MyMap

map image returned from e.g. GetMap()

polys

or of class SpatialPolygons from the package sp

polygons to overlay; these can be either of class PolySet from the package PBSmapping

col

(optional) vector of colors, one for each polygon

border

the color to draw the border. The default, NULL, means to use par("fg"). Use border = NA to omit borders, see polygon

lwd

line width, see par

verbose

level of verbosity

add

start a new plot or add to an existing

textInPolys

text to be displayed inside polygons.

…

further arguments passed to PlotOnStaticMap

See Also

PlotOnStaticMap mypolygon

Examples

# NOT RUN {

if (interactive()){


  #require(PBSmapping);


  shpFile <- paste(system.file(package = "RgoogleMaps"), "/shapes/bg11_d00.shp", sep = "")


  #shpFile <- system.file('bg11_d00.shp', package = "RgoogleMaps");


  


  shp=importShapefile(shpFile,projection="LL");


  bb <- qbbox(lat = shp[,"Y"], lon = shp[,"X"]);


  MyMap <- GetMap.bbox(bb$lonR, bb$latR, destfile = "DC.png");


  PlotPolysOnStaticMap(MyMap, shp, lwd=.5, col = rgb(0.25,0.25,0.25,0.025), add = F);


  


  #Try an open street map:





  mapOSM <- GetMap.OSM(lonR=bb$lonR, latR=bb$latR, scale = 150000, destfile = "DC.png");


  PlotPolysOnStaticMap(mapOSM, shp, lwd=.5, col = rgb(0.75,0.25,0.25,0.15), add = F);





  #North Carolina SIDS data set:


  shpFile <- system.file("shapes/sids.shp", package="maptools");


  shp=importShapefile(shpFile,projection="LL");


  bb <- qbbox(lat = shp[,"Y"], lon = shp[,"X"]);


  MyMap <- GetMap.bbox(bb$lonR, bb$latR, destfile = "SIDS.png");


  #compute regularized SID rate


  sid <- 100*attr(shp, "PolyData")$SID74/(attr(shp, "PolyData")$BIR74+500)


  b <- as.integer(cut(sid, quantile(sid, seq(0,1,length=8)) ));


  b[is.na(b)] <- 1;


  opal <- col2rgb(grey.colors(7), alpha=TRUE)/255; opal["alpha",] <- 0.2;


  shp[,"col"] <- rgb(0.1,0.1,0.1,0.2);


  for (i in 1:length(b)) 


    shp[shp[,"PID"] == i,"col"] <- rgb(opal[1,b[i]],opal[2,b[i]],opal[3,b[i]],opal[4,b[i]]);


  PlotPolysOnStaticMap(MyMap, shp, lwd=.5, col = shp[,"col"], add = F);


  


  #compare the accuracy of this plot to a Google Map overlay:


  library(maptools);


  qk <- SpatialPointsDataFrame(as.data.frame(shp[, c("X","Y")]), as.data.frame(shp[, c("X","Y")]))


  sp::proj4string(qk) <- CRS("+proj=longlat");


  tf <- "NC.counties";


  SGqk <- GE_SpatialGrid(qk)


  png(file=paste(tf, ".png", sep=""), width=SGqk$width, height=SGqk$height,


  bg="transparent")


  par(mar=c(0,0,0,0), xaxs="i", yaxs="i");par(mai = rep(0,4))


  PBSmapping::plotPolys(shp, plt=NULL)


  dev.off()


  maptools::kmlOverlay(SGqk, paste(tf, ".kml", sep=""), paste(tf, ".png", sep=""));


  #This kml file can now be inspected in Google Earth or Google Maps


  


  #or choose an aspect ratio that corresponds better to North Carolina's elongated shape:


  MyMap <- GetMap.bbox(bb$lonR, bb$latR, destfile = "SIDS.png", size = c(640, 320), zoom = 7);


  PlotPolysOnStaticMap(MyMap, shp, lwd=.5, col = shp[,"col"], add = F);


 }


# }