Helping with write a function. Merging shape file with all fields?

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 at cornell.edu 
<mailto:zua3 at 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