added means to ignore units if no valid units are available
added means to ignore units if no valid units are available

low-sky/pyspeckit,dinossimpson/pyspeckit,allisony/pyspeckit,jpinedaf/pyspeckit,e-koch/pyspeckit,vlas-sokolov/pyspeckit,pyspeckit/pyspeckit,keflavich/pyspeckit,low-sky/pyspeckit,jpinedaf/pyspeckit,mikelum/pyspeckit,dinossimpson/pyspeckit,keflavich/pyspeckit,keflavich/pyspeckit-obsolete,pyspeckit/pyspeckit,allisony/pyspeckit,bsipocz/pyspeckit,bsipocz/pyspeckit,e-koch/pyspeckit,mikelum/pyspeckit,vlas-sokolov/pyspeckit