Index: mttroot/mtt/lib/comp/simple/cieqn.m
==================================================================
--- mttroot/mtt/lib/comp/simple/cieqn.m
+++ mttroot/mtt/lib/comp/simple/cieqn.m
@@ -1,9 +1,9 @@
 function structure =  cieqn(name, bond_number,bonds,direction,cr,args, ...
     structure,CorI,eqnfile);
 % cieqn - Equation function for a (multi-port) unicausal C or I component
-% CorI = 1 for C, -1 for I
+% CorI = 1 for C, -1 for I; 0 for ISW
 
 % 
 %     %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 
 %     %%%%% Model Transformation Tools %%%%%
 %     %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
@@ -14,37 +14,54 @@
 % %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 % %% Version control history
 % %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 % %% $Id$
 % %% $Log$
+% %% Revision 1.1  1997/04/09  10:18:26  peterg
+% %% Initial revision
+% %%
 % %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 
 
 % Copyright (c) P.J. Gawthrop, 1996.
 
 if nargin<8
   eqnfile = 'stdout';
 end;
+
+CorIorISW = CorI;
+if CorIorISW==0 % ISW
+   CorI = -1;
+end;
 
 % Find the number of ports
 [ports,junk] = size(bonds);
 
 % Right-hand side causality
 RHS_cause = (bonds(:,1)==CorI*ones(ports,1))*CorI
-state_cause = 0; % State causality
+state_cause = zeros(ports,1); % State causality
 
 for outport = 1:ports
+
+  % Sort out direction
+  if direction(outport,1) == 1
+    sign = '+';
+  else
+    sign = '-';
+  end;
+  
   LHS_number = bond_number(outport);
   if bonds(outport,1) == -CorI % Integral causality on this port
     state = structure(1)+1;
     LHS_cause = CorI;
 
     % Print equation of form x_i = MTTx(i)
     fprintf(eqnfile, '%s := MTTx(%1.0f,1);\n', ...
         varname(name,LHS_number, state_cause), state);
-    % Print equation of form xdot = input
-    fprintf(eqnfile, 'MTTdX(%1.0f,1) := %s;\n', state, ...
+
+    % Print equation of form xdot = input - with sign
+    fprintf(eqnfile, 'MTTdX(%1.0f,1) := %s%s;\n', state, sign, ...
                      varname(name,LHS_number,-LHS_cause));
     % Print equation of form output = CR (state) 
     eqn =  equation(name,cr,args,LHS_number,LHS_cause,outport, ...
                              bond_number,state_cause,1:ports);
     fprintf(eqnfile, '%s',eqn);
@@ -51,13 +68,13 @@
     structure(1) = state;
   else % Derivative causality
     nonstate = structure(2)+1;
     LHS_cause = -CorI;
 
-    % Print equation of form zdot = MTTdz(i)
-    fprintf(eqnfile, '%s := MTTdz(%1.0f,1);\n', ...
-                             varname(name,LHS_number,LHS_cause), ...
+    % Print equation of form zdot = MTTdz(i) -- with sign 
+    fprintf(eqnfile, '%s := %sMTTdz(%1.0f,1);\n', ...
+                             varname(name,LHS_number,LHS_cause), sign, ...
                              nonstate);
     % Print equation of form MTTz(i) = z_i
     fprintf(eqnfile, 'MTTz(%1.0f,1) := %s;\n', nonstate, ...
              varname(name,LHS_number, state_cause));