Changed main function to require specific number of command line arguments
Added some Doxygen comments to specify what the variables mean
collision.cc, working on
finished collision.cc
changed comments in collision.cc
fixed greater than
test
Merge branch 'master' into jw_working_on_main
Yep, this is necessary rge branch 'master' into jw_working_on_main
test
changed main.cc file back
semi-implicit (symplectic) Euler added.  Very similar to Euler
removed unnecessary file
Merge pull request #3 from wally800/master

collision.{h,cc} and euler_semi_implicit.{cc,h} made