how to show polygons from SHP file in Google map?

Yes

First: type ?readShapePoly
If it does not help, use Google, Bing, RSiteSearch, etc.
Third: ask R-sig-geo

natSHP.sp <- readShapePoly("nro2.shp", proj4string=CRS("+init=epsg:2166"))
spplot(natSHP.sp, "NATURRAUMO")

To understand the error, try:
system.file("package="maptools")
system.file("shapes/sids.shp", package="maptools")
and
system.file("nro2.shp", package="maptools")

Best
Torleif

On Thursday 04 June 2009 03:02:44 pm Jian Li wrote:
  

Dear Torleif,

I just tried to produce another SpatialPolygons like nat.sp from SHP file
like this following: natSHP.sp <- readShapePoly(system.file("nro2.shp",
package="maptools")[1], proj4string=CRS("+init=epsg:2166"))

in order to approach it in the same way for saving the information in KML
file

But it doesn't work. Do you know what's going wrong or do you have any
better idea?

The nro2.shp is under
http://jaguar.biologie.hu-berlin.de/~jian/phpMysqlGoogle/arcViewNro2/
available.

greeting,
Jian

    

########################
##Export e00 to Google Earth (png)##
########################

#1: import using RArcInfo

#Set the working directory to where you stored your nat.e00 data
setwd('~/e00data') #Use your own path

#load the RArcInfo library (for functions e00toavc, get.xxx)
require(RArcInfo)

#Convert the e00 to SpatialPolygons
e00toavc('nat.e00', './nat2')
nat.arc <- get.arcdata("./", "nat2")
nat.pal <- get.paldata("./", "nat2")
require(maptools) #Needed for pal2SpatialPolygons
nat.sp <- pal2SpatialPolygons(nat.arc,
	      nat.pal,
	      nat.pal[[1]]$PolygonId[-1],
	      dropPoly1=TRUE,
	      proj4string=CRS("+init=epsg:2166"))

#Transform to longlat, WGS84
require(rgdal)
nat2.sp <- spTransform(nat.sp, CRS("+proj=longlat +ellps=WGS84"))

#Set up metadata
GSG <- GE_SpatialGrid(nat2.sp)

#Ask for the tempdir
tmp.dir <- tempdir()

#To change the resolution (and line width), change res
res <- 5
#Make png-file
png(file=paste(tmp.dir, "/", "nat.png", sep=""), width=GSG$width*res,
height=GSG$height*res,
bg="transparent")
     par(mar=c(0,0,0,0), xaxs="i", yaxs="i")
     plot(nat2.sp, xlim=GSG$xlim, ylim=GSG$ylim, lwd = res)
dev.off()

#And make the Google earth kml-file
kmlOverlay(SGqk, paste(tmp.dir, "/",  "nat.kml", sep=""),
paste(tmp.dir, "/", "nat.png", sep=""))

#Now, see in td, and you have your kml and png.


###########################################
##Export the same data as polygons (still to Google earth)
#The second option is to export as polygons
#(See ?kmlPolygon in maptools)

out <- sapply(slot(nat2.sp, "polygons"), function(x) { kmlPolygon(x,
    name=paste(slot(x, "ID")),
    col="transparent", lwd=5, border='black',
    description=paste(slot(x, "ID"))) })

tf <- tempfile()

kmlFile <- file(paste(tf, ".kml", sep=""), "w")
cat(kmlPolygon(kmlname="MyGPoly",
kmldescription="<i>Masterthesis</i>")$header,
    file=kmlFile, sep="\n")
cat(unlist(out["style",]), file=kmlFile, sep="\n")
cat(unlist(out["content",]), file=kmlFile, sep="\n")
cat(kmlPolygon()$footer, file=kmlFile, sep="\n")
close(kmlFile)
#################

Best wishes
Torleif

On Wednesday 03 June 2009 09:45:45 am Paul Hiemstra wrote:
      

Hi,

You have to do two things, read your data and export it to a format for
Google Earth.

The Cran Spatial Taskview suggests the RArcInfo package to read the e00
files into R. I'm not sure into what format they are loaded. Maybe
readOGR from the rgdal package can also read e00 files, depending on
the GDAL/OGR version you have available.

If you have your vector file in an R session in a SpatialPolygons
object (see the sp-package), the following code shows an example how to
export the data to a format that Google Earth can read:

library(rgdal)
data(meuse)
coordinates(meuse) = ~x+y
proj4string(meuse) = CRS("+init=epsg:28992")
proj4string(meuse)
meuse.ll = spTransform(meuse, CRS("+proj=longlat"))
writeOGR(meuse.ll, "meuse.kml", "meuse.kml", driver="KML")

I'm not sure if the RArcInfo reads the e00 file into a SpatialPolygons
object (Virgillio?), or if it is easy to convert the output from
RArcInfo to an sp-class. rgdal always reads data into an sp-class, but
I'm not sure if this supports the e00 format.

I hope this e-mail provides you with some clues to work with,

cheers and good luck with your thesis,
Paul

Jian Li wrote:
        

Dear r-sig-geo Members,

recently, I've been trying to display the information from a e00 file
(Grauss-Kr?ger coordinatensystem) in Google map but until now no
success.

I would be very appreciated if anyone can help me to solve the
problem which directly concerns my master thesis.

e00 file is under
http://jaguar.biologie.hu-berlin.de/~jian/phpMysqlGoogle/nat.e00
available

Thank you in Advanced

Best Regards,
Jian

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