[R-sig-Geo] problems loading spproj library for transform()

[karl.sommer at dpi.vic.gov.au]

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



|---------+----------------------------------->
|         |           Roger.Bivand at nhh.no     |
|         |           Sent by:                |
|         |           r-sig-geo-bounces at stat.m|
|         |           ath.ethz.ch             |
|         |                                   |
|         |                                   |
|         |           25/05/2006 15:41        |
|         |           Please respond to       |
|         |           Roger.Bivand            |
|         |                                   |
|---------+----------------------------------->
  >------------------------------------------------------------------------------------------------------------------------------|
  |                                                                                                                              |
  |       To:       mdsumner at utas.edu.au                                                                                         |
  |       cc:       r-sig-geo at 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 at 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: Roger.Bivand at nhh.no

_______________________________________________
R-sig-Geo mailing list
R-sig-Geo at stat.math.ethz.ch
https://stat.ethz.ch/mailman/listinfo/r-sig-geo