Filtering shapefile to come up with only one county

writeOGR(Nakuru, dsn= "gis", layer="Nakuru". driver="ESRI Shapefile")

On Sat, 5 Apr 2014, Yuster Ronoh wrote:

Thanks Gordon and Kapo. Gordon I tried your code and it plot the whole
country  but for Kapo it work well and I manage to plot Nakuru county but
I
still have problem in exporting shapefile here in the error message:

writeOGR(Nakuru,dsn="C://Users/symon/Desktop/gis/",layer="Nakuru",driver="ESRI
Shapefile")Error in writeOGR(Nakuru, dsn =
"C://Users/symon/Desktop/gis/", layer = "Nakuru",  :
 Creation of output file failed

This is a known problem under Windows, the dsn should read:

"C:/Users/symon/Desktop/gis"

with no trailing directory separator. Can be replicated with:

library(rgdal)
td <- tempdir()
dsn <- system.file("vectors", package = "rgdal")[1]
cities <- readOGR(dsn=dsn, layer="cities")
td
writeOGR(cities, paste(td, "/", sep=""), "cities",
  driver="ESRI Shapefile")
# Error in writeOGR(cities, paste(td, "/", sep = ""), "cities",
#  driver = "ESRI Shapefile") :
#  Creation of output file failed
writeOGR(cities, td, "cities", driver="ESRI Shapefile")
# works

Roger

On Sat, Apr 5, 2014 at 1:16 AM, Kapo Coulibaly <kmcoulib at gmail.com>
wrote:

Something like this works for me:
counties<-readOGR(dsn=""C://Users/symon/Desktop/gis/",layer="counties")
Nakuru<-subset(counties,COUNTY_NAM=="Nakuru") # make sure the name and
the
content of the columns are spelled correctly
plot(Nakuru) # Plots the county map


You can write the shapefile of Nakuru county with:
writeOGR(Nakuru,dsn=""C://Users/symon/Desktop/gis/",layer="Nakuru",driver="ESRI
Shapefile")



On Fri, Apr 4, 2014 at 1:25 PM, Yuster Ronoh <yuster0 at gmail.com> wrote:

Dear List members
I have a Kenya shapefile with counties.I try to come up with Nakuru
county
map and I try with the below code and got an error.How do i  sub-set to
come up with Nakuru shapefile from the Kenya shapefile
here is my code:

library(maps)

library(maptools)

library(sp)

library(rgdal)

library(ggplot2)

counties<-readShapePoly("C://Users/symon/Desktop/gis/counties.shp")

str(counties)

Nakuru <- fortify(counties, region = "COUNTY_NAM")
str(Nakuru)
unique(counties at data$COUNTY_NAM)

class(counties)

counties at data = counties at data[counties at data$COUNTY_NAME != "NAKURU",]

plot(counties at data)Error in plot.window(...) : need finite 'xlim'

valuesIn addition: Warning messages:1: In min(x) : no non-missing
arguments
to min; returning Inf2: In max(x) : no non-missing arguments to max;
returning -Inf3: In min(x) : no non-missing arguments to min; returning
Inf4: In max(x) : no non-missing arguments to max; returning -Inf


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--
Roger Bivand
Department of Economics, Norwegian School of Economics,
Helleveien 30, N-5045 Bergen, Norway.
voice: +47 55 95 93 55; fax +47 55 95 91 00
e-mail: Roger.Bivand at nhh.no