ADDED   mttroot/mtt/lib/comp/simple/AE_cause.m
Index: mttroot/mtt/lib/comp/simple/AE_cause.m
==================================================================
--- /dev/null
+++ mttroot/mtt/lib/comp/simple/AE_cause.m
@@ -0,0 +1,69 @@
+function [bonds,status] = AE_cause(bonds);
+% AE_cause - Causality for Flow amplifier component
+% 
+%     %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 
+%     %%%%% Model Transformation Tools %%%%%
+%     %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% 
+% Matlab function  AE_cause
+% [bonds,status] = AE_cause(bonds)
+
+% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% %% Version control history
+% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% %% $Id$
+% %% $Log$
+% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+
+% Copyright (c) P.J. Gawthrop, 1996.
+
+
+status = -1;
+
+% Check that there are exactly two bonds.
+if check_bonds(bonds,2,'AE')==0
+  return
+end
+
+% There are 2 ports; extract the information
+e_1 = bonds(1,1);
+f_1 = bonds(1,2);
+e_2 = bonds(2,1);
+f_2 = bonds(2,2);
+
+% Port 1 must impose (zero) flow and port 2 have flow imposed
+if (f_1==-1)|(f_2==1) % Conflict
+  status = 1;
+ else 					% Do the rest of the causality
+
+   if f_1 == 0 				% Set port 1 effort
+     f_1 = 1;
+   end;
+   
+   if f_2 == 0 				% Set port 2 effort
+     f_2 = -1;
+   end;
+   
+   number_set = sum(sum([e_1 e_2]~=zeros(1,2) ));
+   if number_set==0 			% Under causal
+     status = -1;
+   elseif number_set==1 		% Set the causality
+     if e_1 == 0
+       e_1 = -e_2;
+     else
+       e_2 = -e_1;
+     end
+     status = 0;
+   elseif number_set==2 		% Check the causality
+     if e_1==-e_2
+       status = 0;
+     else
+       status = 1;
+     end
+ end;
+end;
+ 
+ bonds = [e_1 f_1
+           e_2 f_2];
+

ADDED   mttroot/mtt/lib/comp/simple/AF_cause.m
Index: mttroot/mtt/lib/comp/simple/AF_cause.m
==================================================================
--- /dev/null
+++ mttroot/mtt/lib/comp/simple/AF_cause.m
@@ -0,0 +1,67 @@
+function [bonds,status] = AF_cause(bonds);
+% AF_cause - Causality for Flow amplifier component
+% 
+%     %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 
+%     %%%%% Model Transformation Tools %%%%%
+%     %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% 
+% Matlab function  AF_cause
+% [bonds,status] = AF_cause(bonds)
+
+% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% %% Version control history
+% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% %% $Id$
+% %% $Log$
+% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+
+% Copyright (c) P.J. Gawthrop, 1996.
+
+status = -1;
+
+% Check that there are exactly two bonds.
+if check_bonds(bonds,2,'AF')==0
+  return
+end
+
+% There are 2 ports; extract the information
+e_1 = bonds(1,1);
+f_1 = bonds(1,2);
+e_2 = bonds(2,1);
+f_2 = bonds(2,2);
+
+% Port 1 must impose (zero) effort and port 2 have effort imposed
+if (e_1==1)|(e_2==-1) % Conflict
+  status = 1;
+ else 					% Do the rest of the causality
+
+   if e_1 == 0 				% Set port 1 effort
+     e_1 = -1;
+   end;
+   
+   if e_2 == 0 				% Set port 2 effort
+     e_2 = 1;
+   end;
+   
+   number_set = sum(sum([f_1 f_2]~=zeros(1,2) ));
+   if number_set==0 			% Under causal
+     status = -1;
+   elseif number_set==1 		% Set the causality
+     if f_1 == 0
+       f_1 = -f_2;
+     else
+       f_2 = -f_1;
+     end
+     status = 0;
+   elseif number_set==2 		% Check the causality
+     if f_1==-f_2
+       status = 0;
+     else
+       status = 1;
+     end
+ end;
+end;
+ 
+ bonds = [e_1 f_1
+           e_2 f_2];

ADDED   mttroot/mtt/lib/comp/simple/R_cause.m
Index: mttroot/mtt/lib/comp/simple/R_cause.m
==================================================================
--- /dev/null
+++ mttroot/mtt/lib/comp/simple/R_cause.m
@@ -0,0 +1,49 @@
+function [bonds,status] = R_cause(bonds);
+% R_cause - Causality function for a (multi-port) unicausal R component
+% 
+%     %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 
+%     %%%%% Model Transformation Tools %%%%%
+%     %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% 
+% Matlab function  R_cause
+% [bonds,status] = R_cause(bonds)
+
+% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% %% Version control history
+% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% %% $Id$
+% %% $Log$
+% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+
+% Copyright (c) P.J. Gawthrop, 1996.
+ 
+
+% Find the number of ports
+[ports,junk] = size(bonds);
+
+% default undercausal status
+statuses = -ones(ports,1);
+
+% Force unicausality
+for i = 1:ports
+  if (bonds(i,1)~=0)&(bonds(i,2)~=0) % Both bonds set
+    statuses(i) = bonds(i,1)~=bonds(i,2);
+  elseif bonds(i,2)~=0               % Bond 1 set
+    bonds(i,1) = bonds(i,2);
+    statuses(i) = 0;
+  elseif bonds(i,1)~=0               % Bond 2 set
+    bonds(i,2) = bonds(i,1);
+    statuses(i) = 0;
+  end;
+end;
+
+if max(statuses)==1
+  status = 1;
+elseif min(statuses)==-1
+  status = -1;
+else
+  status = 0;
+end;
+  
+

ADDED   mttroot/mtt/lib/comp/simple/check_bonds.m
Index: mttroot/mtt/lib/comp/simple/check_bonds.m
==================================================================
--- /dev/null
+++ mttroot/mtt/lib/comp/simple/check_bonds.m
@@ -0,0 +1,28 @@
+function ok = check_bonds(bonds,n,component);
+% check_bonds - check to see correct number (n) of bonds.
+% 
+%     %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 
+%     %%%%% Model Transformation Tools %%%%%
+%     %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% 
+% Matlab function  check_bonds
+% err = check_bonds(bonds,n);
+
+% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% %% Version control history
+% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% %% $Id$
+% %% $Log$
+% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+
+% Copyright (c) P.J. Gawthrop, 1996.
+% Check that there are exactly two bonds.
+[n_bonds,cols] = size(bonds);
+if n_bonds~=n
+  mtt_info(sprintf('MTT error: %s must have %1.0f (not %1.0f) bonds', ...
+      component, n, n_bonds));
+  ok=0;
+else
+  ok=1;
+end

ADDED   mttroot/mtt/lib/comp/simple/oneeqn.m
Index: mttroot/mtt/lib/comp/simple/oneeqn.m
==================================================================
--- /dev/null
+++ mttroot/mtt/lib/comp/simple/oneeqn.m
@@ -0,0 +1,28 @@
+function  oneeqn(name,LHS_number,LHS_cause,RHS_number,RHS_cause,cr,args, ...
+    eqnfile);
+% oneeqn - prints a single equation
+% 
+%     %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 
+%     %%%%% Model Transformation Tools %%%%%
+%     %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% 
+% Matlab function  oneeqn
+% oneeqn(name,LHS_number,LHS_cause,RHS_number,RHS_cause,cr,args,eqnfile)
+
+% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% %% Version control history
+% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% %% $Id$
+% %% $Log$
+% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+
+
+if nargin<7
+  eqnfile = 'stdout';
+end;
+
+
+fprintf(eqnfile, '%s := %s;\n', ...
+    varname(name, LHS_number,LHS_cause), ...
+    cr2name(name,RHS_number,LHS_cause,RHS_cause,cr,args));