On Fri, 29 Jan 2010, Cédric Briand wrote:
Dear list members
We are using R 2.10.1 and rgdal Version: 0.6-20, and are working with
windows XP.
If you mean the Windows binary rgdal package, then the answer is in
file.show(system.file("README", package="rgdal"))
file.show(system.file("README.windows", package="rgdal"))
The Windows binary package builds the minimal set of drivers, with only
one external dependency (expat for reading GPX and KML). The file refered
to describes how you might build rgdal from source, using FWTools or
OSGEO4W as the provider of GDAL and its dependent DLLs. If you do try this
out (look for the chunk beginning: "Initial notes for OSGeo4W"), and if:
source(system.file("OSGeo4W_test", package="rgdal"), echo=TRUE)
works, as well as PostGIS access, please let me know.
Roger
Following the nice example found at
http://wiki.intamap.org/index.php/PostGIS<http://wiki.intamap.org/index.php/PostGIS>
we tried to connect to our postgres database
PS. That example was run on Linux with GDAL built with PostGIS, and rgdal
installed as a source package.
library(rgdal)
trial = readOGR("PG:dbname=CCM", "riversegments")
This does not work. We have tried to use ogr2ogr and examples found at
http://www.bostongis.com/?content_name=ogr_cheatsheet
and they work fine particularly we were able to connect to our database using
the following script
C:\OSGeo4W\bin\ogr2ogr -f "ESRI Shapefile" C:\base\basesig\essai.shp PG:"host=localhost
user=postgres dbname=CCM password=postgres port=5433" "riversegments
As this works we translated the more complex dsn into the rgdal command line
require(rgdal)
readOGR(dsn="PG:host=locahost user=postgres dbname=CCM password=postgres
port=5433",layer="riversegments")
but it always returns a "Cannot open file" error :
require(rgdal)
Le chargement a n?cessit? le package : rgdal
Le chargement a n?cessit? le package : sp
Geospatial Data Abstraction Library extensions to R successfully loaded
Loaded GDAL runtime: GDAL 1.6.2, released 2009/07/31
Path to GDAL shared files: C:/Program Files/R/R-2.10.0/library/rgdal/gdal
Loaded PROJ.4 runtime: Rel. 4.6.1, 21 August 2008
Path to PROJ.4 shared files: C:/Program Files/R/R-2.10.0/library/rgdal/proj
readOGR(dsn="PG:host=localhost dbname=CCM user=postgres passwd=postgres
port=5433",layer="riversegments")
Erreur dans ogrInfo(dsn = dsn, layer = layer, input_field_name_encoding =
input_field_name_encoding) : Cannot open file
The ogrInfo in command line found at 'C:\OSGeo4W\bin\ogrInfo.exe' does seem to
work (it does not return any error)
The reason behind this failure seems to be that PostgresSQL is not listed in
the drivers availaible with the package.
ogrDrivers()
name write
1 AVCBin FALSE
2 AVCE00 FALSE
3 BNA TRUE
4 CSV TRUE
5 DGN TRUE
6 ESRI Shapefile TRUE
7 Geoconcept TRUE
8 GeoJSON TRUE
9 GML TRUE
10 GMT TRUE
11 GPX TRUE
12 KML TRUE
13 MapInfo File TRUE
14 Memory TRUE
15 REC FALSE
16 S57 TRUE
17 SDTS FALSE
18 TIGER TRUE
19 UK .NTF FALSE
20 VRT FALSE
21 XPlane FALSE
After many trials we are at a loss on how to add a driver to the drivers in R.
So any hint would be really valuable.
C?dric
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--
Roger Bivand
Economic Geography Section, Department of Economics, Norwegian School of
Economics and Business Administration, Helleveien 30, N-5045 Bergen,
Norway. voice: +47 55 95 93 55; fax +47 55 95 95 43
e-mail: roger.biv...@nhh.no
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