thanks for the prompt reply the method spTransform() worked
I now have an attribute file of class SpatiaPointsDataFrame with EM38 readings. I also have a separate shape file of class SpatialPolygonsDataFrame which I imported form an ESRI shape file using the readOGR() method of rgdal. I would like to superpose the two files in a plot but so far have not been successful in lining them up satisfactorily. I am not sure if the misalignement is due to my misguided plotting method p1 <- spplot(x, c("var")) #attribute data p2 <- spplot (x2) # shapefile print(p1, split = c(1,1,1,1), more = TRUE) print(p2, split = c(1,1,1,1), more = FALSE) or due to the fact that the projections of the two files differ. I am not sure how to extract projection information from the shape file. any hints would be appreciated Karl |---------+-----------------------------------> | | [EMAIL PROTECTED] | | | Sent by: | | | [EMAIL PROTECTED]| | | ath.ethz.ch | | | | | | | | | 25/05/2006 15:41 | | | Please respond to | | | Roger.Bivand | | | | |---------+-----------------------------------> >------------------------------------------------------------------------------------------------------------------------------| | | | To: [EMAIL PROTECTED] | | cc: r-sig-geo@stat.math.ethz.ch | | Subject: Re: [R-sig-Geo] problems loading spproj library for transform() | >------------------------------------------------------------------------------------------------------------------------------| On Thu, 25 May 2006, Michael Sumner wrote: > Hello > > I have the same problem, I've been meaning to explore further before > posting, but since spproj is not on CRAN I don't think I've missed > something obvious. This seems to be related to rgdal 0.4-4: > In rgdal, try running example("spTransform-methods") - if it works, use spTransform() instead of transform(). Sorry for the muddle. Roger > ## using data from ?project example > > library(rgdal) > > ## project works OK > data(state) > res <- project(cbind(state.center$x, state.center$y), "+proj=lcc > +lat_1=48 +lat_2=33 +lon_0=-100") > res1 <- project(res, "+proj=lcc +lat_1=48 +lat_2=33 +lon_0=-100", > inv=TRUE) > > ## but transform does not > > res <- SpatialPoints(res, CRS("+proj=lcc +lat_1=48 +lat_2=33 +lon_0 =-100")) > > sessionInfo() > #Version 2.3.0 (2006-04-24) > #i386-pc-mingw32 > > #attached base packages: > #[1] "methods" "stats" "graphics" "grDevices" "utils" "datasets" > #[7] "base" > > #other attached packages: > # rgdal pixmap abind sp > # "0.4-4" "0.4-4" "1.1-0" "0.8-14" > > > transform(res, CRS("+proj=longlat")) > #Loading required package: spproj > #Error in transform(res, CRS("+proj=longlat")) : > # for using (coordinate) transform on objects deriving from > Spatial, library spproj is required > #In addition: Warning message: > #there is no package called 'spproj' in: library(package, lib.loc = > lib.loc, character.only = TRUE, logical = TRUE, > > _______________________________________________ > R-sig-Geo mailing list > R-sig-Geo@stat.math.ethz.ch > https://stat.ethz.ch/mailman/listinfo/r-sig-geo > -- 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: [EMAIL PROTECTED] _______________________________________________ R-sig-Geo mailing list R-sig-Geo@stat.math.ethz.ch https://stat.ethz.ch/mailman/listinfo/r-sig-geo _______________________________________________ R-sig-Geo mailing list R-sig-Geo@stat.math.ethz.ch https://stat.ethz.ch/mailman/listinfo/r-sig-geo