Since you can install rgdal it would be best to go that way (I had completely missed that you obviously had access to rgdal::spTransform, please provide the code you are using as asked by the mailing list guidelines).
library(rgdal) See ?readOGR You need a layer name, which can just be the file name without extension: nc.river<-readOGR("~/hydromaj/hydromaj_arc.shp", "hydromaj_arc") Then do proj4string(nc.river) to see that it's not NA before proceeding with spTransform. (Re-projecting is not straightforward and you should really be checking carefully at every step against the needs of your project, we can't advise past the basics of just running code. ) Cheers, Mike. On Tue, Feb 26, 2013 at 1:14 PM, Migun Shakya <microbea...@gmail.com> wrote: > Hi Mike, > > I tried the rgdal:readOGR, but got an error. > >> nc.river<-readOGR("~/hydromaj/hydromaj_arc.shp") > Error in readOGR("~/hydromaj/hydromaj_arc.shp") : > missing layer > > Sorry, I am not very familiar with the data structure, but i am > looking at the spatialreference.org. Lets see what i get. > > Thanks, > Migun > > Here is the .prj file content for hydromaj_arc.prj > > PROJCS["NAD_1983_StatePlane_North_Carolina_FIPS_3200",GEOGCS["GCS_North_American_1983",DATUM["D_North_American_1983",SPHEROID["GRS_1980",6378137.0,298.257222101]],PRIMEM["Greenwich",0.0],UNIT["Degree",0.0174532925199433]],PROJECTION["Lambert_Conformal_Conic"],PARAMETER["False_Easting",609601.22],PARAMETER["False_Northing",0.0],PARAMETER["Central_Meridian",-79.0],PARAMETER["Standard_Parallel_1",34.33333333333334],PARAMETER["Standard_Parallel_2",36.16666666666666],PARAMETER["Latitude_Of_Origin",33.75],UNIT["Meter",1.0]] > > On Mon, Feb 25, 2013 at 9:01 PM, Michael Sumner <mdsum...@gmail.com> wrote: >> You need an input projection on the data, it doesn't know what you are >> transforming FROM. >> >> Did you read this with maptools::readShapePoly? Try with rgdal:readOGR >> so you get the projection automatically with the object. >> >> I cannot download the data from the link you provide, but if you post >> the text of the .prj files here someone will be able to give you R >> code to set it without re-reading. (Explore for yourself on >> spatialreference.org). >> >> Also, "lat,lon" requires a datum like any map projection - you'll need >> to find out if you should stay with NAD83 or convert to WGS84 as in >> Erin's code. >> >> Cheers, Mike. >> >> >> >> On Tue, Feb 26, 2013 at 12:45 PM, Migun Shakya <microbea...@gmail.com> wrote: >>> Hi Erin, >>> I tried that but ended up getting this error. Does the spTransform >>> function requires the data to be as data.frame? >>> Here is what i did to read the data >>> >>> library(maptools) >>> library(rgdal) >>> nc.river<-readShapeSpatial("~/hydromaj/hydromaj_arc.shp") #reading the >>> shape file >>> >>> nc1.wgs84 <- spTransform(nc.river,CRS("+proj=longlat +datum=WGS84")) >>> Error in spTransform(xSP, CRSobj, ...) : >>> No transformation possible from NA reference system >>> >>> >>> Thanks again >>> Migee >>> >>> On Mon, Feb 25, 2013 at 5:47 PM, Hodgess, Erin <hodge...@uhd.edu> wrote: >>>> Hi! >>>> >>>> Suppose your data set is called nc1.df. >>>> >>>> Then you can do: >>>> library(rgdal) >>>> nc1.wgs84 <- spTransform(nc1.df,CRS("+proj=longlat +datum=WGS84")) >>>> >>>> >>>> ________________________________________ >>>> From: r-sig-geo-boun...@r-project.org [r-sig-geo-boun...@r-project.org] on >>>> behalf of Migun Shakya [microbea...@gmail.com] >>>> Sent: Monday, February 25, 2013 4:21 PM >>>> To: r-sig-geo@r-project.org >>>> Subject: [R-sig-Geo] converting from NAD83 datum to lat,lon >>>> >>>> Hi all, >>>> >>>> Is there a way/package/trick to convert the NAD83 formatted file to >>>> lat lon format? >>>> >>>> I downloaded the "Major Hydrography" dataset from NC,USA to plot >>>> rivers into a NC map. However, the dataset is in NAD83 or in state >>>> plane projection, but i need it to be in lat/lon. >>>> >>>> >>>> Any help would be great. >>>> >>>> >>>> Thanks >>>> Migee >>>> >>>> >>>> dataset can be found in: >>>> http://data.nconemap.com/geoportal/catalog/search/resource/details.page?uuid=%7B2515713B-2CA0-476F-863F-61441A9D6F70%7D >>>> >>>> >>>> The downloaded dataset consist of >>>> hydromaj_arc.dbf >>>> hydromaj_arc.prj >>>> hydromaj_arc.shp >>>> hydromaj_arc.shx >>>> hydromaj_arc.txt >>>> hydromaj_poly.dbf >>>> hydromaj_poly.prj >>>> hydromaj_poly.shp >>>> hydromaj_poly.shx >>>> >>>> _______________________________________________ >>>> R-sig-Geo mailing list >>>> R-sig-Geo@r-project.org >>>> https://stat.ethz.ch/mailman/listinfo/r-sig-geo >>> >>> _______________________________________________ >>> R-sig-Geo mailing list >>> R-sig-Geo@r-project.org >>> https://stat.ethz.ch/mailman/listinfo/r-sig-geo >> >> >> >> -- >> Michael Sumner >> Hobart, Australia >> e-mail: mdsum...@gmail.com -- Michael Sumner Hobart, Australia e-mail: mdsum...@gmail.com _______________________________________________ R-sig-Geo mailing list R-sig-Geo@r-project.org https://stat.ethz.ch/mailman/listinfo/r-sig-geo