PlotPolysOnStaticMap: plots polygons on map

In iNZightVIT/RgoogleMaps: Overlays on Google map tiles in R

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

Author(s)

Markus Loecher

See Also

PlotOnStaticMap mypolygon

Examples

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);


 }

iNZightVIT/RgoogleMaps documentation built on May 17, 2019, 10:09 p.m.