Hi All, I'm trying to write a Ruby app to read the new and fantastic NASA ASTER Elevation DEM. This is of course in GeoTiff format.
I'm wondering if anyone has examples in any language of using GDAL to read a particular location's data from a geotiff file? I can do the calculations to figure out which of the 3601x3601 data elements I need to read is, but I can't find an example of using GDAL to load only that pixel's information. If anyone has an example that would be great. I'm also having issues installing GDAL on OS X even when using macports. I can build and install fine without the ruby bindings, but using them (via editing the port file to include --with-ruby) gives me: libtool: link: /usr/bin/g++-4.0 gdal_wrap.o -o gdal.so -L/opt/local/lib -L/System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib -L/opt/local -L/usr/X11/lib -L/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_release_ports_science_gdal/work/gdal-1.6.0 /opt/local/lib/libgdal.dylib /opt/local/lib/libproj.dylib -lm /opt/local/lib/libgif.dylib /opt/local/lib/libSM.dylib /opt/local/lib/libICE.dylib /opt/local/lib/libX11.dylib /opt/local/lib/libXau.dylib /opt/local/lib/libXdmcp.dylib -lgeotiff /opt/local/lib/libtiff.dylib /opt/local/lib/libjpeg.dylib -lc /opt/local/lib/libpng12.dylib -lz -ldl -lruby Undefined symbols: "_main", referenced from: start in crt1.10.5.o ld: symbol(s) not found collect2: ld returned 1 exit status make[3]: *** [gdal.so] Error 1 make[2]: *** [build] Error 2 make[1]: *** [build] Error 2 make: *** [swig-modules] Error 2 Error: Status 1 encountered during processing. I'm assuming it can't find ruby to link to, but not quite sure how to resolve this. Does --with-ruby have any extra undocumented options? If I figure it out I'd be happy to add to the Ruby WIKI page - who should I email to get access/contribute information? Thanks in advance. Regards, Adam. _______________________________________________ gdal-dev mailing list gdal-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/gdal-dev