Zia,

Does this work?
Set your working directory and your output filename.

library(rgdal)
library(maptools)
setwd("C:/test")                                              # CHANGE THIS
combinedShp <- "C:/test/combined.shp"           # CHANGE THIS

# obtain shapefiles in current directory
files <- list.files(pattern = "shp")
uid <- 1

# get polygons from first file
poly.data <- readOGR(files[1], gsub(".shp","",files[1]))
n <- length(slot(poly.data, "polygons"))
poly.data <- spChFIDs(poly.data, as.character(uid:(uid+n-1)))
uid <- uid + n

# add polygons from remaining files
for (i in 2:length(files)) {
   temp.data <- readOGR(files[i], gsub(".shp","",files[i]))
   n <- length(slot(temp.data, "polygons"))
   temp.data <- spChFIDs(temp.data, as.character(uid:(uid+n-1)))
   uid <- uid + n
   poly.data <- spRbind(poly.data,temp.data)
}

writeOGR(poly.data, dsn=combinedShp, layer="combined", driver="ESRI
Shapefile")


Matt Beard
Purdue University




On Fri, Jan 22, 2010 at 10:45 PM, Zia Ahmed <zua3@cornell.edu> wrote:

> Hi Matt:
> With help of Jim Holtman  (my R Guru!), I am able to modified your code for
> selecting  particular type  of shape  files from  different folders and able
> to  combine them together. Thank you so much!
> However, final polygon does not contain any filed  (suppose county name,
> FIPS code  etc) of  the shape files those I used for merging . How do I keep
> these fields  in  my final polygon.   Any idea?
> Thanks
> Zia
>
>

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