ADDED   mttroot/mtt/lib/comp/simple/SS_eqn.m
Index: mttroot/mtt/lib/comp/simple/SS_eqn.m
==================================================================
--- /dev/null
+++ mttroot/mtt/lib/comp/simple/SS_eqn.m
@@ -0,0 +1,84 @@
+function structure =  SS_eqn(bond_number,bonds,direction,cr,args, ...
+                            structure,eqnfile);
+
+% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% %% Version control history
+% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% %% $Id$
+% %% $Log$
+% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+if nargin<7
+  eqnfile = 'stdout';
+end;
+
+% The string 'cr' contains the effort attributes;  
+% 'arg' contains the flow attributes. 
+% external indicates an external variable
+% internal indicates an internal variable
+% anything else is the name of a constant.
+
+effort_attribute = cr;
+flow_attribute = args;
+
+inputs = structure(3);
+outputs = structure(4);
+
+% Effort
+if strcmp(effort_attribute, 'external')
+  if bonds(1,1)==-1 % Source
+    inputs = inputs+1;
+    fprintf(eqnfile, '%s := MTTu(%1.0f,1);\n', ...
+        varname(bond_number,1),inputs);
+  else % Sensor
+    outputs = outputs+1;
+    fprintf(eqnfile, 'MTTy(%1.0f,1) := %s;\n', ...
+        outputs, varname(bond_number,1));
+  end;
+elseif strcmp(effort_attribute, 'internal')
+  % Do nothing
+else % named constant
+  if bonds(1,1)==-1 % Source
+    fprintf(eqnfile, '%s := %s;\n', ...
+        varname(bond_number,1), effort_attribute);
+  else % Sensor
+  % THIS STILL NEEDS DOING!
+  mtt_info('Constant outputs not implemented yet!');
+  end;
+end;
+
+% Flow
+if strcmp(flow_attribute, 'external')
+  if bonds(1,2)==1 % Source
+    inputs = inputs+1;
+    fprintf(eqnfile, '%s := MTTu(%1.0f,1);\n', varname(bond_number,-1),inputs);
+  else % Sensor
+    outputs = outputs+1;
+    fprintf(eqnfile, 'MTTy(%1.0f,1) := %s;\n', outputs, ...
+        varname(bond_number,-1));
+  end;
+elseif strcmp(flow_attribute, 'internal')
+  % Do nothing
+else % Named constant
+  if bonds(1,2)==1 % Source
+    fprintf(eqnfile, '%s := %s;\n', ...
+	varname(bond_number,-1), flow_attribute);
+  else % Sensor
+  % THIS STILL NEEDS DOING!
+  mtt_info('Zero outputs not implemented yet!');
+  end;
+end;
+
+  
+structure(3) = inputs;
+structure(4) = outputs;
+  
+
+  
+  
+
+
+
+
+
+