! Module file: get_subgroups
!
! CNS module
! **********
!
! Authors: Axel Brunger and Paul Adams
!
! copyright Yale University
!
! Function:
!    Find subgroups of atom types in the given selection
!    The type for each subgroup is returned along with the
!    number of groups in a compound variable.
!
! Requirements:
!    The molecular topology and coordinates are well defined
!    This can be called only from the main level

module {get_subgroups}

(
selection;
subgroups;
)

set message ? end
evaluate ($message_old=$result)
set echo ? end
evaluate ($echo_old=$result)
if ( $log_level = verbose ) then
  set echo=on message=normal end
else
  set echo=off message=off end
end if

set display=? end
evaluate ($curr_display=$result)

checkversion 1.3

evaluate ($num=0)

for $id in id ( &selection ) loop main

  show (chemical) ( id $id )
  evaluate ($type=$result)

  if ( &EXIST%subgroups.$type = false ) then

    evaluate ($num=$num+1)

    evaluate (&subgroups.$type=true)
    evaluate (&subgroups.type.$num=$type)

  end if

end loop main

evaluate (&subgroups.num=$num)

set message=$message_old echo=$echo_old end