Re: [GRASS-user] Mapping Africa in an equal area projection
Corrado wrote: I would like to use it to map distribution of some specimen at a resolution of 100 km x 100 km (or even down to 25 km x 25 km). I gathered some information, and ended up with: 1) Sinusoidal 2) Equatorial Lambert Azimuthal Equal Area 3) Albers Equal Area (Conic) 4) Mollweide 5) Cylindrical Equal Area I do not really know which one to choose. What do you recommend? I would suggest to ask on the PROJ.4 mailing list. http://proj.osgeo.org For each of them, which ellipsoid and datum would you choose? if you are creating something custom probably stick with WGS84. as for your point data, you can import it into a lat/lon WGS84 location (epsg:4326) as points with v.in.ascii. once you have set up your new projection you can pull that file over with v.proj. r.in.xyz wants a text file as input, so you'd have to re-export (with projected coords this time) with v.out.ascii.db (from wiki addons) or v.out.ascii + a little cut paste in a spreadsheet. alternatively you can reproject your text file from lat/lon WGS84 to (whatever) with the 'm.proj -i' module from within the new projection, or cs2cs from proj4. if using v.in.ascii to create a points map some stuff to play with is v.kernel and v.surf.rst. Hamish ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
[GRASS-user] Mapping Africa in an equal area projection
Dear friends, I would like to use it to map distribution of some specimen at a resolution of 100 km x 100 km (or even down to 25 km x 25 km). I gathered some information, and ended up with: 1) Sinusoidal 2) Equatorial Lambert Azimuthal Equal Area 3) Albers Equal Area (Conic) 4) Mollweide 5) Cylindrical Equal Area I do not really know which one to choose. What do you recommend? For each of them, which ellipsoid and datum would you choose? Regards -- Corrado Topi Global Climate Change Biodiversity Indicators Area 18,Department of Biology University of York, York, YO10 5YW, UK Phone: + 44 (0) 1904 328645, E-mail: [EMAIL PROTECTED] ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
