function [bonds,components,n_vector_bonds] = rbg2abg(name,rbonds,rstrokes,rcomponents,\
				      port_coord,port_name,\
				      infofile,errorfile)

  ## ###############################################################
  ## ## Version control history
  ## ###############################################################
  ## ## $Id$
  ## ## $Log$
  ## ## Revision 1.44  1999/10/19 00:05:44  peterg
  ## ## Now defaults junction ports when only one specified (for vector junctions)
  ## ##
  ## ## Revision 1.43  1999/10/18 04:08:46  peterg
  ## ## Now computes n_vector_bonds -- number apparent (maybe vector) bonds per component.
  ## ## Neeeded to vectorise junctions.
  ## ##
  ## ## Revision 1.42  1999/08/25 21:45:03  peterg
  ## ## Spurious start to vector 0 and 1
  ## ##

    if ((comp_type=="0")||(comp_type=="1")) # A junction
      disp("---- default junctions ---- ");
      junction_names = 0;
      for j=1:n_comp_bonds
	port_name_index = getindex(port_bond,signed_bond_list(j));
	if port_name_index>0
	  junction_port_name = port_name(port_name_index,:);
	  named_bond_index = j;
	  junction_names++;
	endif
      endfor

      if junction_names==1	# one named port
	mtt_info(sprintf("Defaulting all ports on junction %s to %s", comp_name, junction_port_name));
	## Make the other n-1 names the same.
	junction_port_name = mtt_strip_name(junction_port_name);
	for j=1:n_comp_bonds;
	  if j!=named_bond_index
	    port_name = [port_name; ["[" junction_port_name "]"]]; # add to list
	    [port_name_index,junk] = size(port_name); # the corresponding index
	    port_bond(port_name_index,:) = signed_bond_list(j); # add to port bond
	  endif
	endfor
      elseif (junction_names!=0)&&(junction_names!=n_comp_bonds) # not allowed
	mtt_error(sprintf("Junction %s must have 0, 1 or %i port labels", comp_name,n_comp_bonds),errorfile);
      endif
      port_name = port_name
    else			# Not a junction
      for j=1:n_comp_bonds
	signed_bond = signed_bond_list(j);
	port_name_index = getindex(port_bond,signed_bond);
	port_direction = sign(signed_bond);
	
	if port_name_index==0	# There is no port on this bond - so try

	  mtt_info(["Defaulting port name [" port_name_i "]\t on component " \
		    comp_name " (" comp_type ")" ],infofile);
	  port_name = [port_name; ["[" port_name_i "]"]];	# add to list
	  [port_name_index,junk] = size(port_name); # the corresponding
				# index
	  port_bond(port_name_index,:) = signed_bond; # add to port bond
	else  
	  port_name_i = mtt_strip_name(port_name(port_name_index,:));
	  ## port_name_i = deblank(port_name(port_name_index,:));
	  ## port_name_i = port_name_i(2:length(port_name_i)-1) # strip []
	endif
	
	
	## Replace by alias -- if any
    	eval( ["alias = ", comp_type, '_alias';]); # Get aliases
    	if is_struct(alias)		# are there any aliases
          if struct_contains(alias,port_name_i) # Is this an alias?