Make sure you created libavh_olo.a with option DDTYPE=ddfun90 in the directory ../ Set the correct compiler and paths in the makefile here. DDF90MOD should be the directory with the mod-files of ddfun90 DDF90LIB should be the directory with the ddfun90 library DDF90 should be the ddfun90 library The example is set up to include LoopTools. If you do not have LoopTools available, choose "WITHLT = no" in the makefile. If you do want to use LoopTools, choose the right option for the version you use: is version>=2.6 yes or no? Then execute "make" followed by "./example.exe < input"