The issue here is not exactly how to plot maps through R, as I have found already a pretty nice example here, but rather how to make it work. In fact, I am unable to load library rgdal:
library(rgdal)
Error in library(rgdal) : there is no package called ‘rgdal’
However, when I try to install the above package manually, I get the following error:
....
configure: error: proj_api.h not found in standard or given locations.
ERROR: configuration failed for package ‘rgdal’
* removing ‘/home/eualin/R/i686-pc-linux-gnu-library/2.15/rgdal’
Warning in install.packages : installation of package ‘/home/eualin/Downloads/rgdal_0.8-5.tar.gz’ had non-zero exit status
Any input welcome!
Answer
I f you look at the package page on CRAN, you will see the following :
SystemRequirements: for building from source: GDAL >= 1.7.1 library from http://trac.osgeo.org/gdal/wiki/DownloadSource and PROJ.4 (proj >= 4.4.9) from http://trac.osgeo.org/proj/; GDAL OSX frameworks built by William Kyngesburye at http://www.kyngchaos.com/ may be used for source installs on OSX.
As you seem to be under Linux, you always build package from source, so you will have to install the corresponding libraries on your system. If you are under Mint, Ubuntu or another Debian derivative, you can do :
$ sudo apt-get install libgdal1-dev libproj-dev
One tip that can be useful, still under a Debian based system, is to install the apt-file package and run :
$ sudo apt-file update
Then, when you get an error such as :
configure: error: proj_api.h not found in standard or given locations.
You can use the following command to find which package you must install to get the missing file :
$ apt-file search proj_api.h
libproj-dev: /usr/include/proj_api.h