ADDED   mttroot/mtt/bin/trans/m/mtt_check_sigs.m
Index: mttroot/mtt/bin/trans/m/mtt_check_sigs.m
==================================================================
--- /dev/null
+++ mttroot/mtt/bin/trans/m/mtt_check_sigs.m
@@ -0,0 +1,24 @@
+function N = mtt_check_sigs (outsig,insigs)
+
+  ## usage:  N = mtt_check_sigs (outsig,insigs)
+  ##
+  ## 
+
+  ##  A signal has the columns: bond number signal causality (+1 or -1)
+  ##  and component port number
+
+  M=3;
+
+  ## Sanity check
+  [N_out,M_out] = size(outsig);
+  if N_out<>1
+    error("There must be exactly one outbond");
+  endif
+  [N_in,M_in] = size(insigs);
+  if (M_out!=M)||(M_in!=M)
+    error(sprintf("There must be exactly %i elements to a bond (number, causality, port)",M));
+  endif
+
+  N = N_in;
+
+endfunction

ADDED   mttroot/mtt/bin/trans/m/mtt_component_eqn.m
Index: mttroot/mtt/bin/trans/m/mtt_component_eqn.m
==================================================================
--- /dev/null
+++ mttroot/mtt/bin/trans/m/mtt_component_eqn.m
@@ -0,0 +1,292 @@
+function [known] = mtt_component_eqn (fullname, port, causality, known)
+
+  ## function [known] = mtt_component_eqn (fullname, port, causality, known)
+  ##
+  ## Recursively finds the equations giving the signal of specified
+  ## causality on the specified port of component named "name" within
+  ## subsystem Name 
+
+  ## fullname:  name of component and subsystem
+  ## port: port number of component
+  ## causality: effort or flow
+  ## know_list: list of components already known
+
+  ## Data structures.
+  ## A signal is a row vector containing three numbers:
+  ##   Index -- a unique (within a subsystem) signed integer
+  ##            abs(index) is the unique bond number, sign is the direction.
+  ##   Causality -- 1 for effort, -1 for flow
+  ##   Port -- the port of the component to which it is connected.
+  ## 
+
+  [Name,name] = mtt_subname(fullname); # Split fullname
+
+  SD = "__";			# Subsystem delimiter
+  CD = "\n%%";			# Comment delimiter
+
+  DEBUG = 0;
+
+  if DEBUG
+    disp("=======================================");
+    fullname, name, Name, port,causality,known
+  endif
+  
+  eqn="## No equation -- something wrong"; # Default
+
+  if length(known)<2		# Invalid
+    known = "  ";
+  endif
+  
+  ## File containing data structure
+  cbg_file = sprintf("%s_cbg",Name);
+
+  if (exist(cbg_file)==0)
+    error(sprintf("mtt_component_eqn: subystem \"%s\" does not exist", Name));
+  endif
+  
+  ## Subsystem data structure
+  cbg = eval(sprintf("%s;", cbg_file));
+
+  if struct_contains (cbg, "ports")
+    ## Combine ports with the other subsystems
+    for [component_structure, component] = cbg.ports
+      eval(sprintf("cbg.subsystems.%s=cbg.ports.%s;",component,component));
+    endfor
+  endif
+  
+
+  ## Call to a subsystem (represented by name="")
+  if strcmp(name,"")
+    if !struct_contains(cbg,"portlist")
+      N_ports = 0;
+    else
+      [N_ports,M_ports] = size(cbg.portlist);
+    endif
+    
+    if port>N_ports
+      error(sprintf("port (%i) > N_ports (%i)", port, N_ports));
+    else			# Get name and find equation
+      name = deblank(cbg.portlist(port,:));
+      if DEBUG
+	disp("----> lower-level system")
+      endif
+      known = mtt_component_eqn (mtt_fullname(Name,name), 1, causality, known);
+      return
+    endif
+  endif
+  
+
+  ## Other causality representations
+  if strcmp(causality,"effort")
+    i_cause = 1;
+    othercausality = "flow";
+    index_cause = 1;
+    cause = "e";
+  elseif strcmp(causality,"flow")
+    i_cause = -1;
+    othercausality = "effort";
+    index_cause = 2;
+    cause = "f";
+  else
+    error(sprintf("mtt_component_eqn: causality %s invalid", causality));
+  endif
+  
+  ## A useful composite name
+  name_port_cause = sprintf("%s_%i_%s",name, port, cause);
+  full_name_port_cause = mtt_fullname(Name,name_port_cause);
+
+  ## If value is known, don't do anything.
+  if findstr(sprintf(" %s ", full_name_port_cause), known)>0
+    eqn = sprintf("%s The %s signal on port %i of %s is known already", \
+		  CD, causality, port, name);
+    return
+  else			# Add to list
+    known = sprintf("%s %s", known, full_name_port_cause);
+  endif
+  
+  
+  
+  ## Component type
+  comp_type = eval(sprintf("cbg.subsystems.%s.type;", name));
+  if DEBUG
+    comp_type
+  endif
+  
+  ## Component cr
+  cr = eval(sprintf("cbg.subsystems.%s.cr;", name));
+
+  ## Component arg
+  arg = eval(sprintf("cbg.subsystems.%s.arg;", name));
+
+  ## To which bond(s) is the component connected?
+  connections = eval(sprintf("cbg.subsystems.%s.connections;", name));
+  bond_list = abs(connections);	# Unsigned list 
+  out_bond_number = bond_list(port);	# The bond at the output of this component
+  direction = sign(connections); # Bond directions
+  directions = direction'*[1 1]; 
+
+  ## List of system bonds
+  bonds = cbg.bonds;
+
+  ## List of component bond causality (component-orientated causality)
+  comp_bonds = bonds(bond_list,:).*directions; # Component bonds
+
+  ## What components are at the other ends of the in bonds?
+  ## Effort
+  [in_e_bonds,in_e_components,in_e_ports,N_e] = mtt_component_inputs \
+      (name,comp_type,causality,"effort",comp_bonds,connections,cbg);
+  ## Flow
+  [in_f_bonds,in_f_components,in_f_ports,N_f] = mtt_component_inputs \
+      (name,comp_type,causality,"flow",comp_bonds,connections,cbg);
+
+
+  ##Composite values
+  N_ef = N_e + N_f;
+  in_ef_bonds = [in_e_bonds; in_f_bonds];
+  in_ef_components = [in_e_components; in_f_components];
+  in_ef_ports = [in_e_ports; in_f_ports];
+  in_causality = [ones(N_e,1); -ones(N_f,1)];
+
+  ## Lists of signals relevant to this component
+  outsig = [out_bond_number i_cause port];
+  insigs = [in_ef_bonds in_causality in_ef_ports];
+  innames = in_ef_components;
+
+  if DEBUG
+    outsig
+    insigs
+    innames
+  endif
+  
+  ## Is the signal the output of a port?
+  is_port_output = 0;			# Default
+  if struct_contains (cbg, "ports")
+    if struct_contains (cbg.ports,name)
+      is_port_output = (outsig(2)!=insigs(1,2));
+    endif
+  endif
+  
+  if is_port_output
+    ## Which port (number) is it?
+    [N_ports,M_ports] = size(cbg.portlist);
+    for i=1:N_ports
+      if strcmp(deblank(cbg.portlist(i,:)), name)
+	port_index = i;
+	break;
+      endif
+    endfor
+
+    ## File containing data structure
+    NAME = mtt_subname(Name);
+    Cbg_file = sprintf("%s_cbg",NAME);
+
+    if (exist(Cbg_file)==0)
+      error(sprintf("mtt_component_eqn: subsystem %s does not exist", NAME));
+    endif
+    
+    ## System data structure
+    Cbg = eval(sprintf("%s;", Cbg_file));
+    
+    
+    ## And to which component (at higher level) is it connected?
+    [new_Name,new_name] = mtt_subname(Name);
+    port_bond = eval(sprintf("Cbg.subsystems.%s.connections(%i);", new_name, port_index));
+    [in_name, in_port, in_bond] = mtt_other_end (new_name,port_bond,Cbg);
+
+    ## Find its equation
+    if DEBUG
+      disp("----> higher level system")
+    endif
+    
+
+    known = mtt_component_eqn (mtt_fullname(new_Name,in_name), in_port, causality, known);
+
+    LHS = Source_seqn ("external",Name);
+    RHS = varname(NAME, abs(in_bond), i_cause);
+    eqn = sprintf("%s%s%s := %s;", LHS, SD, name, RHS);
+
+    if !DEBUG
+      comment = sprintf("%s PORT", CD);
+      disp(sprintf("%s\n%s",comment, eqn));
+    endif
+
+  endif
+  
+
+  ## Handle special components
+  if strcmp(comp_type,"0")||strcmp(comp_type,"1") # Junctions
+    [eqn,insigs,innames] = junction_seqn (comp_type,Name, outsig, \
+					  insigs, innames);
+  else				# Everything else
+    if exist(sprintf("%s_cause", comp_type)) # Simple component
+      ## Do the equations
+      [eqn,insigs,innames] = eval(sprintf("%s_seqn (Name, name, cr, arg, outsig, insigs, innames);", comp_type));
+    else			# Compound component
+      new_NAME = Name;
+      new_Name = mtt_fullname(Name,name);
+      new_name = "";
+      
+      ## File containing data structure
+      Cbg_file = sprintf("%s_cbg",new_Name);
+
+      if (exist(Cbg_file)==0)
+	error(sprintf("mtt_component_eqn: subsystem %s does not exist", new_Name));
+      endif
+      
+      ## System data structure
+      Cbg = eval(sprintf("%s;", Cbg_file));
+      port_name = Cbg.portlist(port,:);
+
+      LHS = varname(Name, outsig(1,1), outsig(1,2));
+      RHS = Sensor_seqn ("external",new_Name);
+      eqn = sprintf("%s := %s%s%s;", LHS, RHS, SD, port_name);
+
+      if DEBUG
+	disp("----> same-level subsystem")
+      endif
+
+      [known] = mtt_component_eqn \
+   	  (mtt_fullname(new_Name,new_name), port, causality, known);
+      
+    endif
+  endif
+
+  comment = \
+      sprintf("%s Equation for %s signal on port %i of %s (%s), subsystem %s.", \
+     	      CD, causality, port, name, comp_type, Name);
+
+  if DEBUG
+    disp(sprintf("%s\n%s",comment, eqn));
+  endif
+  
+  is_external = mtt_is_external(comp_type,outsig, insigs, is_port_output);
+
+  if !is_external
+    ## Find the corresponding input equations
+    [N_other,M_other] = size(insigs);
+    for i = 1:N_other
+      if insigs(i,2)==1
+	other_causality = "effort";
+      else
+	other_causality = "flow";
+      endif
+
+      other_port = insigs(i,3);
+      other_name = deblank(innames(i,:));
+      if DEBUG
+	disp("----> same-level component")
+      endif
+      
+
+      [known] = mtt_component_eqn \
+    	  (mtt_fullname(Name,other_name), other_port, other_causality, known);
+    endfor
+  endif
+
+  ## Write this signal
+  ##comment_2 = sprintf("Connected to:%s", in_component_list);
+  if !DEBUG
+    disp(sprintf("%s\n%s",comment, eqn));
+  endif
+
+endfunction

ADDED   mttroot/mtt/bin/trans/m/mtt_component_inputs.m
Index: mttroot/mtt/bin/trans/m/mtt_component_inputs.m
==================================================================
--- /dev/null
+++ mttroot/mtt/bin/trans/m/mtt_component_inputs.m
@@ -0,0 +1,30 @@
+function [in_bonds,in_components,in_ports,N] = mtt_component_inputs \
+      (name,comp_type, out_causality, causality,comp_bonds,bond_list,cbg)
+
+  ## usage:  [in_bonds,in_components,in_ports,N] = mtt_component_inputs 
+  ##      (name,comp_type, out_causality, causality,comp_bonds,bond_list,cbg)
+  ##
+  ## 
+
+
+  ## Other causality representations  if strcmp(causality,"effort")
+  if strcmp(causality,"effort")
+    i_cause = 1;
+    othercausality = "flow";
+    index_cause = 1;
+  elseif strcmp(causality,"flow")
+    i_cause = -1;
+    othercausality = "effort";
+    index_cause = 2;
+  else
+    error(sprintf("mtt_component_eqn: causality %s invalid", causality));
+  endif
+  
+  in_index = find(comp_bonds(:,index_cause)==i_cause);
+  all_in_bonds = bond_list(in_index);
+  N_all = length(all_in_bonds);
+
+  ## What components are at the other ends of the in bonds?
+  [in_components,in_ports,in_bonds] = mtt_other_end (name,all_in_bonds,cbg);
+  N = length(in_bonds);
+endfunction

ADDED   mttroot/mtt/bin/trans/m/mtt_fullname.m
Index: mttroot/mtt/bin/trans/m/mtt_fullname.m
==================================================================
--- /dev/null
+++ mttroot/mtt/bin/trans/m/mtt_fullname.m
@@ -0,0 +1,10 @@
+function fullname = mtt_fullname (subname,compname)
+
+  ## usage:  fullname = mtt_fullname (subname,compname)
+  ##
+  ## Finds the standard mtt name of the component
+
+  delim = "__";
+  fullname = sprintf("%s%s%s", subname, delim, compname);
+
+endfunction

ADDED   mttroot/mtt/bin/trans/m/mtt_is_external.m
Index: mttroot/mtt/bin/trans/m/mtt_is_external.m
==================================================================
--- /dev/null
+++ mttroot/mtt/bin/trans/m/mtt_is_external.m
@@ -0,0 +1,19 @@
+function is_external = mtt_is_external (comp_type,outsig, insigs, is_port)
+
+  ## usage:  is_external = mtt_is_external (comp_type,outsig, insigs)
+  ##
+  ## 
+
+  if nargin<4
+    is_port = 0;
+  endif
+
+  is_external = 0;			# Default
+
+  if strcmp(comp_type,"SS");
+    is_external = insigs(1,2)!=outsig(2);
+  else
+    is_external = 0;
+  endif
+
+endfunction

ADDED   mttroot/mtt/bin/trans/m/mtt_name2names.m
Index: mttroot/mtt/bin/trans/m/mtt_name2names.m
==================================================================
--- /dev/null
+++ mttroot/mtt/bin/trans/m/mtt_name2names.m
@@ -0,0 +1,12 @@
+function names = mtt_name2names (name)
+
+  ## usage:  names = mtt_name2names (name)
+  ##
+  ## Converts standard mtt name to an array of subsystem names
+
+  ## Copyright (C) 2003 by Peter J. Gawthrop
+
+  delim ="__";			# MTT delimiter
+  names = split(name,delim);
+
+endfunction

ADDED   mttroot/mtt/bin/trans/m/mtt_names2name.m
Index: mttroot/mtt/bin/trans/m/mtt_names2name.m
==================================================================
--- /dev/null
+++ mttroot/mtt/bin/trans/m/mtt_names2name.m
@@ -0,0 +1,16 @@
+function name = mtt_names2name (names)
+
+  ## usage:  name = names2name (names)
+  ##
+  ## Converts array of subsystem names to a standard mtt name
+
+  delim ="__";			# MTT delimiter
+
+  [n,m] = size(names);
+  name = deblank(names(1,:));
+
+  for i = 2:n
+    name = sprintf("%s%s%s", name, delim, deblank(names(i,:)));
+  endfor
+
+endfunction

ADDED   mttroot/mtt/bin/trans/m/mtt_other_causality.m
Index: mttroot/mtt/bin/trans/m/mtt_other_causality.m
==================================================================
--- /dev/null
+++ mttroot/mtt/bin/trans/m/mtt_other_causality.m
@@ -0,0 +1,21 @@
+function other = mtt_other_causality (causality)
+
+  ## usage:  other = mtt_other_causality (causality)
+  ##
+  ## 
+
+  causality = deblank(causality);
+  if strcmp(causality,"effort");
+    other = "flow";
+  elseif strcmp(causality,"flow");
+    other = "effort";
+  elseif strcmp(causality,"e");
+    other = "f";
+  elseif strcmp(causality,"f");
+    other = "e";
+  else
+    error(sprintf("Causality \"%s\" not recognised",causality));
+  endif
+  
+
+endfunction

ADDED   mttroot/mtt/bin/trans/m/mtt_other_end.m
Index: mttroot/mtt/bin/trans/m/mtt_other_end.m
==================================================================
--- /dev/null
+++ mttroot/mtt/bin/trans/m/mtt_other_end.m
@@ -0,0 +1,27 @@
+function [in_components,in_ports,in_bonds] = mtt_other_end (name,all_in_bonds,cbg);
+
+  ## usage:  [in_components,in_ports,in_bonds] = mtt_other_end (name,all_in_bonds,cbg);
+  ##
+  ## 
+
+  ## What components are at the other ends of the in bonds?
+  in_components = "";
+  in_ports = [];
+  in_bonds = [];
+  in_direction = [];
+  for i = 1:length(all_in_bonds);
+    for [component_structure, component] = cbg.subsystems
+      if !strcmp(name,component)
+	other_connections = component_structure.connections;
+	one = ones(size(other_connections));
+	port = find(abs(all_in_bonds(i))*one==abs(other_connections));
+	if (length(port)==1)
+	  in_components = [in_components; component];
+	  in_bonds = [in_bonds; all_in_bonds(i)];
+	  in_ports = [in_ports; port];
+	endif
+      endif
+    endfor
+  endfor
+
+endfunction

ADDED   mttroot/mtt/bin/trans/m/mtt_subname.m
Index: mttroot/mtt/bin/trans/m/mtt_subname.m
==================================================================
--- /dev/null
+++ mttroot/mtt/bin/trans/m/mtt_subname.m
@@ -0,0 +1,20 @@
+function [subname, compname] = mtt_subname (name)
+
+  ## usage:  subname = mtt_subname (name)
+  ##
+  ## Finds the subsystem name from the component name
+  ## Copyright (C) 2003 by Peter J. Gawthrop
+
+
+  names = mtt_name2names(name);
+  [n,m] = size(names);
+
+  if n<2			# Simple name
+    subname = "";
+    compname = name;
+  else				# Compound name
+    subname = mtt_names2name(names(1:n-1,:));
+    compname = deblank(names(n,:));
+  endif
+
+endfunction