function [bonds,components] = rbg2abg(rbonds,rstrokes,rcomponents,rports,infofile)

% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %% Version control history
% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %% $Id$
% %% $Log$
% %% Revision 1.4  1996/08/24 18:00:33  peter
% %% Fixed bug with finding ports.
% %%
% %% Revision 1.3  1996/08/09 08:26:35  peter
% %% Cosmetic tidy up.
% %%
% %% Revision 1.2  1996/08/04 18:37:57  peter
% %% Fixed  no causal strokes bug.
% %%
% %% Revision 1.1  1996/08/04 18:30:14  peter

else
  fnum = fopen(infofile, 'w');
end;

% Xfig scaling factor
scale = 1200.0;

% Rotation matrix
rot = [0 -1; 1 0];

% Find number of strokes
[n_strokes,columns] = size(rstrokes);
if (columns ~= 4)&(n_strokes>0)
  error('Incorrect rstrokes matrix: must have 4 columns');
end;

    arrow_end;
 
% Locate the bond end nearest to each port
for i = 1:n_ports
  near_bond = adjbond(rports(i,1:2),arrow_end,other_end);
  port_near_bond(i,:) = [near_bond, rports(i,3)];
end;


% Locate the components at the ends of each bond
for i = 1:n_bonds
  comp_near_bond(i,:) = adjcomp(arrow_end(i,:),other_end(i,:),rcomponents);
end;


% Produce a list of bonds on each component - sorted if explicit port numbers
for i = 1:n_components    
  [index,n] = getindex(comp_near_bond,i);
    % Error message in case we need it!
  port_error = sprintf(... 
      'Component at (%1.3f,%1.3f) has inconsistent port numbers', ...
      rcomponents(i,1)/scale, rcomponents(i,2)/scale);

  if index(1,1) ~= 0 % Then its a genuine component 
    one = ones(n,1);
    bond_list = index(:,1); %  bond at component
    bond_end = index(:,2);  % which end of bond at component?


    % Default sort of bonds (ie no change)
    sort_index = [1:n]'; 
    
    if n_ports>0
      % Are the component ports numbered? (either they all are or none are)
      k=0;
      for j = 1:n
	b = bond_list(j); e = bond_end(j);
	% Find all ports on this bond
	[port_indices,m] = getindex(port_near_bond(:,1),b);
	% Now find the one at this end
	for l=1:m
	  port_index = port_indices(l);
	  if port_near_bond(port_index,2)==e
	    break;
	  end;
	end;
	% and put the corresponding number in the list
	k=k+1;
	port_number(k,1) = port_near_bond(port_index,3);
      end;

	% Must have a lable for each port or non at all
      if k==n
	[sorted,sort_index]=sort(port_number);
	if sum(sorted==[1:n]')~=n % The there is something wrong
	  mtt_info(port_error,fnum);
	  mtt_info(sprintf('\t it must have ports from 1:%1.0f\n', n), fnum);
	end;
      elseif k~=0
	mtt_info(port_error,fnum);


	mtt_info(sprintf('\t it must have 0 or %1.0f ports\n', n), fnum);
      end;
 
    end;
  end;

  % direction is 1 if arrow at component else -1
  direction = -sign(index(:,2)-1.5*one);
  signed_bond_list = bond_list.*direction;