add 'ammonia_func' as an optional parameter for the restricted_tex
add 'ammonia_func' as an optional parameter for the restricted_tex

low-sky/pyspeckit,low-sky/pyspeckit,jpinedaf/pyspeckit,pyspeckit/pyspeckit,pyspeckit/pyspeckit,e-koch/pyspeckit,keflavich/pyspeckit,keflavich/pyspeckit,e-koch/pyspeckit,jpinedaf/pyspeckit