function structure = SS_eqn(name,bond_number,bonds,direction,cr,args, ...
structure,filenum);
% SS_eqn - equations for SS component
%
% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %%%%% Model Transformation Tools %%%%%
% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% Matlab function SS_eqn
% structure = SS_eqn(name,bond_number,bonds,direction,cr,args, ...
% structure,filenum);
% Copyright (c) P.J. Gawthrop, 1996.
% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %% Version control history
% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %% $Id$
% %% $Log$
% %% Revision 1.8 1996/12/10 16:52:29 peterg
% %% Detect null string using strcmp, not length.
% %% Put filnum argument to mtt_info.
% %%
% %% Revision 1.7 1996/12/07 17:17:40 peterg
% %% Added some ;
% %%
% %% Revision 1.6 1996/12/05 09:49:09 peterg
% %% Explicit computation of port number from string.
% %%
% %% Revision 1.5 1996/12/04 21:27:53 peterg
% %% Replaced str2num by sprintf
% %%
% %% Revision 1.4 1996/08/18 20:06:21 peter
% %% Included zero outputs.
% %%
% %% Revision 1.3 1996/08/09 14:08:04 peter
% %% Empty effort and flow attributes replaced by 'external'.
% %%
% %% Revision 1.2 1996/08/08 16:38:19 peter
% %% Changed to filenumer type of fprintf
% %%
% %% Revision 1.1 1996/08/08 16:19:08 peter
% %% Initial revision
% %%
% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% 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.
% Blank is taken to be external
% If its a numbered port:
% cr contains 'MTT_port'
% arg contains port number
STDerr = 2; % Standard output
effort_attribute = cr;
flow_attribute = args;
if strcmp(effort_attribute,'')
effort_attribute = 'external';
end;
if strcmp(flow_attribute,'')
flow_attribute = 'external';
end;
inputs = structure(3);
outputs = structure(4);
zero_outputs = structure(5);
if strcmp(effort_attribute, 'MTT_port') % Its a numbered port
% Convert string to number
port_number = abs(flow_attribute)-abs('0');
% Effort
if bonds(1,1)==-1 % Source
fprintf(filenum, '%s := %s_MTTu%d;\n', ...
varname(name, bond_number,1), name, port_number);
else % Sensor
fprintf(filenum, '%s_MTTy%d := %s;\n', ...
name, port_number, varname(name, bond_number,1));
end;
% Flow
if bonds(1,2)==1 % Source
fprintf(filenum, '%s := %s_MTTu%d;\n', ...
varname(name, bond_number,-1), name, port_number);
else % Sensor
fprintf(filenum, '%s_MTTy%d := %s;\n', ...
name, port_number, varname(name, bond_number,-1));
end;
return
end;
% Effort
if strcmp(effort_attribute, 'external')
if bonds(1,1)==-1 % Source
inputs = inputs+1;
fprintf(filenum, '%s := MTTu(%d,1);\n', ...
varname(name, bond_number,1),inputs);
else % Sensor
outputs = outputs+1;
fprintf(filenum, 'MTTy(%d,1) := %s;\n', ...
outputs, varname(name, bond_number,1));
end;
elseif strcmp(effort_attribute, 'internal')
% Do nothing
else % named constant
if bonds(1,1)==-1 % Source
fprintf(filenum, '%s := %s;\n', ...
varname(name, bond_number,1), effort_attribute);
else % Sensor
if strcmp(effort_attribute, 'zero') %Zero output
zero_outputs = zero_outputs + 1;
fprintf(filenum, 'MTTyz%d := %s;\n', ...
zero_outputs, varname(name, bond_number,1));
fprintf(filenum, '%s := MTTUi%d;\n', ...
varname(name, bond_number,-1), zero_outputs);
else
mtt_info([effort_attribute, ' not appropriate for an output '],STDerr);
end;
end;
end;
% Flow
if strcmp(flow_attribute, 'external')
if bonds(1,2)==1 % Source
inputs = inputs+1;
fprintf(filenum, '%s := MTTu(%d,1);\n', varname(name, bond_number,-1),inputs);
else % Sensor
outputs = outputs+1;
fprintf(filenum, 'MTTy(%d,1) := %s;\n', outputs, ...
varname(name, bond_number,-1));
end;
elseif strcmp(flow_attribute, 'internal')
% Do nothing
else % Named constant
if bonds(1,2)==1 % Source
fprintf(filenum, '%s := %s;\n', ...
varname(name, bond_number,-1), flow_attribute);
else % Sensor
if strcmp(flow_attribute, 'zero') %Zero output
zero_outputs = zero_outputs + 1;
fprintf(filenum, 'MTTyz%d := %s;\n', ...
zero_outputs, varname(name, bond_number,-1));
fprintf(filenum, '%s := MTTUi%d;\n', ...
varname(name, bond_number,1), zero_outputs);
else
mtt_info([effort_attribute, ' not appropriate for an output '], STDerr);
end;
end;
end;