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

% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %% Version control history
% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %% $Id$
% %% $Log$
% %% Revision 1.1  1996/08/04 18:30:14  peter
% %% Initial revision
% %%
% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%


if nargin<5
  infofile='stdout';
end;

  % Write out bond list sorted by port number (if any)
  for j = 1:length(sort_index)
    jj = sort_index(j);
    components(i,j) = signed_bond_list(jj);
  end;
end;

% Find out location of centre and ends of stroke.
if n_strokes>0
  causality = zeros(n_bonds,2);
% Deduce causality from the strokes (if any).
causality = zeros(n_bonds,2);
if n_strokes>0
  % Find out location of centre and ends of stroke.
  stroke_end_1 = [rstrokes(:,1) rstrokes(:,2)];
  stroke_end_2 = [rstrokes(:,3) rstrokes(:,4)];
  
  stroke_centre = (stroke_end_1 + stroke_end_2)/2;
  stroke_vector = (stroke_end_1 - stroke_end_2);
  stroke_length = length2d(stroke_vector);
end;

% Deduce bond causality from the strokes 
for i = 1:n_strokes
  stroke = [stroke_centre(i,:)
  for i = 1:n_strokes
    stroke = [stroke_centre(i,:) 
    stroke_end_1(i,:)
    stroke_end_2(i,:)];


  % Find the nearest bond end.
  [index,distance] = adjbond(stroke(1,:),arrow_end,other_end);
  if (distance>2*stroke_length(i))
    info = sprintf('Stroke at (%4.3f,%4.3f) is %4.3f away from the nearest bond\n', ...
    % Find the nearest bond end.
    [index,distance] = adjbond(stroke(1,:),arrow_end,other_end);
    if (distance>2*stroke_length(i))
      info = sprintf('Stroke at (%4.3f,%4.3f) is %4.3f away from the nearest bond\n', ...
	stroke(1,1)/scale, stroke(1,2)/scale, distance/scale);
  end;
    end;
  
  % Bond end coordinates
  j = index(1,1);
  which_end = index(1,2)==1;
  bond_end = arrow_end(j,:)*which_end + other_end(j,:)*(1-which_end);
    % Bond end coordinates
    j = index(1,1);
    which_end = index(1,2)==1;
    bond_end = arrow_end(j,:)*which_end + other_end(j,:)*(1-which_end);
  
  % Now decide which bit of the stroke is nearest
  stroke_index = adjbond(bond_end,stroke,zeros(size(stroke)));
    % Now decide which bit of the stroke is nearest
    stroke_index = adjbond(bond_end,stroke,zeros(size(stroke)));
  
  if stroke_index(1)==1 % uni-causal stroke
    causality(j,1:2) = (2*which_end-1)*[1 1];
  else % bicausal stroke
    % Find out whether stroke is on flow side of bond
    stroke_direction = stroke(1,:) - stroke(stroke_index(1),:);
    flow_side = stroke_direction*arrow_vector(j,:)'>0;
    causality(j,1+flow_side) = 2*which_end-1;
  end;
  
    if stroke_index(1)==1 % uni-causal stroke
      causality(j,1:2) = (2*which_end-1)*[1 1];
    else % bicausal stroke
      % Find out whether stroke is on flow side of bond
      stroke_direction = stroke(1,:) - stroke(stroke_index(1),:);
      flow_side = stroke_direction*arrow_vector(j,:)'>0;
      causality(j,1+flow_side) = 2*which_end-1;
    end;
  end;
end;

bonds = causality;