Re: [R] How to write a shapefile with projection
Hi Patrick, Thanks for letting me know. I mostly use rgdal to read and write rasters so until now i kind of ignore other functionality. Unfortunately i supposed that a package dedicated to shapefiles would be the answer and had the functionality i needed. But rgdal does a nice job in saving my files as i need. It is good to know how to add the projection file to the shapefiles for the future, if it is not generated from the onset. Thanks again, Monica Date: Sat, 5 Nov 2011 14:27:29 +0100 From: patrick.giraud...@univ-fcomte.fr To: pisican...@hotmail.com CC: r-help@r-project.org Subject: re: How to write a shapefile with projection Hi, Sorry i have put such a detailed question to the list about writing a shapefile with projection. I realized that if i use writeOGR from rgdal and not the other write shapefile functions i can get a shapefile with projection recognized by ArcGIS. The command is (in case anybody wonders): ?writeOGR(crest.sp, I:\\LA_levee\\Shape, llev_crest_pts6, driver = ESRI Shapefile) where crest.sp is a spatial point data frame with projection. Thanks, Monica Indeed. writePointsShape() does not write the projection file, but using the function showWKT from rgdal, you can also create one like that: writePointsShape(crest.sp,crest) cat(showWKT(proj4string(crest.sp)),file=crest.prj) Patrick __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
Re: [R] How to write a shapefile with projection
Hi, Sorry i have put such a detailed question to the list about writing a shapefile with projection. I realized that if i use writeOGR from rgdal and not the other write shapefile functions i can get a shapefile with projection recognized by ArcGIS. The command is (in case anybody wonders): ?writeOGR(crest.sp, I:\\LA_levee\\Shape, llev_crest_pts6, driver = ESRI Shapefile) where crest.sp is a spatial point data frame with projection. Thanks, Monica Indeed. writePointsShape() does not write the projection file, but using the function showWKT from rgdal, you can also create one like that: writePointsShape(crest.sp,crest) cat(showWKT(proj4string(crest.sp)),file=crest.prj) Patrick __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
[R] How to write a shapefile with projection
Hi, I am trying to write a shapefile with projection. I have my data in a data.frame called try and consists in xy coordinates and a numerical attribute value z1. Libraries loaded are: sp, rgdal, raster, maptools head(try) x y z1 1 610237.1 3375751 8.221 2 610236.1 3375750 8.153 3 610236.1 3375749 8.275 4 610236.1 3375748 8.251 5 610236.1 3375747 8.217 6 610236.1 3375746 8.196 #Get the projection from a raster named llev I have loaded before: crs - projection(llev) # get a spatial point data frame from my data crest.sp - SpatialPointsDataFrame(try[,1:2], try, proj4string=CRS(crs)) summary(crest.sp) Object of class SpatialPointsDataFrame Coordinates: min max x 610235.1 610354.1 y 3374862.4 3375751.4 Is projected: TRUE proj4string : [+proj=utm +zone=15 +ellps=GRS80 +datum=NAD83 +units=m +no_defs +towgs84=0,0,0] Number of points: 890 Data attributes: x y z1 Min. : 610235 Min. : 3374862 Min.: 6.966 1st Qu.:610269 1st Qu.:3375085 1st Qu.:7.570 Median :610298 Median :3375307 Median :7.901 Mean :610300 Mean :3375307 Mean :7.882 3rd Qu.:610334 3rd Qu.:3375529 3rd Qu.:8.180 Max. :610354 Max. :3375751 Max. :8.756 #write the shapefile writePointsShape(crest.sp, I:/LA_levee/Shape/llev_crest_pts6) If I load this shapefile in ArcGIS is has no projection. I also looked at the write.shapefile command from shapefiles library and again I get a file without projection. Is there any way to write the projection for the shapefile in R? Probably I can do something in ArcGIS, but I would like to have my shapefile from R complete. Thanks, Monica __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
[R] How to write a shapefile with projection - problem solved
Hi, Sorry i have put such a detailed question to the list about writing a shapefile with projection. I realized that if i use writeOGR from rgdal and not the other write shapefile functions i can get a shapefile with projection recognized by ArcGIS. The command is (in case anybody wonders): writeOGR(crest.sp, I:\\LA_levee\\Shape, llev_crest_pts6, driver = ESRI Shapefile) where crest.sp is a spatial point data frame with projection. Thanks, Monica __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
