ADDED   mttroot/mtt/bin/trans/m/rbg2abg.m
Index: mttroot/mtt/bin/trans/m/rbg2abg.m
==================================================================
--- /dev/null
+++ mttroot/mtt/bin/trans/m/rbg2abg.m
@@ -0,0 +1,154 @@
+function [bonds,components] = rbg2abg(rbonds,rstrokes,rcomponents,rports,infofile)
+
+% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% %% Version control history
+% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% %% $Id$
+% %% $Log$
+% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+
+if nargin<5
+  infofile='stdout';
+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;
+
+% Find number of bonds
+[n_bonds,columns] = size(rbonds);
+if (columns ~= 6)&(n_bonds>0)
+  error('Incorrect rbonds matrix: must have 6 columns');
+end;
+
+% Find number of components
+[n_components,columns] = size(rcomponents);
+
+% Find number of ports
+[n_ports,columns] = size(rports);
+
+% Determine coordinates of the arrow end of the bond and the other end
+other_end_1 = rbonds(:,1:2);
+arrow_end = rbonds(:,3:4);
+other_end_2 = rbonds(:,5:6);
+
+distance_1 = length2d(other_end_1 - arrow_end);
+distance_2 = length2d(other_end_2 - arrow_end);
+which_end = (distance_1>distance_2)*[1 1];
+one = ones(size(which_end));
+other_end = which_end.*other_end_1 + (one-which_end).*other_end_2;
+arrow_vector = ( which_end.*other_end_2 + (one-which_end).*other_end_1 ) - ...
+    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);
+
+  if index(1,1) ~= 0 % Then its a genuine component 
+    one = ones(n,1);
+    bond_list = index(:,1);
+    
+    % 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
+	[port_index,m] = getindex(port_near_bond(:,1),bond_list(j));
+	if m==1 % exactly one number on this bond
+	  if index(j,2)==port_near_bond(port_index,2) % same end
+	    k=k+1;
+	    port_number(k,1) = port_near_bond(port_index,3);
+	  end;
+	end;
+      end;
+      
+      % Must have a lable for each port or non at all
+      if k==n
+	[junk,sort_index]=sort(port_number);
+      elseif k~=0
+	info = sprintf(... 
+	    'Component at (%1.3f,%1.3f) has inconsistent port numbers', ...
+	    rcomponents(i,1)/scale, rcomponents(i,2)/scale);
+	mtt_info(info,infofile);
+      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;
+  
+  % 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);
+  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,:)
+    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', ...
+	stroke(1,1)/scale, stroke(1,2)/scale, distance/scale);
+  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)));
+  
+  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;
+
+bonds = causality;