function engine 
 
 
   % Define engine configuration and drive geometric parameters. 
 
 
   % Israel Urieli 4/14/02 
 
 
   % Modified 6/14/2016 to include free-piston beta engine 
 
 
   % s)inusoidal, y)oke r)ocker-V (all alpha engines) 
 
 
   global 
 
 
  engine_type 
 
   global 
 
 
  new fid 
 
   % new data file 
 
 
  engine_type = 
 
   'u' 
 
 
  ; 
 
   while 
 
 
  (strncmp(engine_type, 
 
   'u' 
 
 
  ,1)) 
 
   if 
 
 
  (strncmp(new, 
 
   'y' 
 
 
  ,1)) 
 
  fprintf( 
 
   'Available engine types are:\n' 
 
 
  ); 
 
  fprintf( 
 
   '   s)inusoidal drive\n' 
 
 
  ); 
 
  fprintf( 
 
   '   y)oke drive (Ross)\n' 
 
 
  ); 
 
  fprintf( 
 
   '   r)ocker-V drive (Ross)\n' 
 
 
  ); 
 
  fprintf( 
 
   '   b)eta drive (Free piston)\n' 
 
 
  ); 
 
  engine_type = input( 
 
   'enter engine type ' 
 
 
  , 
 
   's' 
 
 
  ); 
 
  fprintf(fid, 
 
   '%c\n' 
 
 
  , engine_type(1)); 
 
   else 
 
 
  engine_type = fscanf(fid, 
 
   '%c' 
 
 
  ,1); 
 
   end 
 
 
   if 
 
 
  (strncmp(engine_type, 
 
   's' 
 
 
  ,1)) 
 
  sindrive; 
 
   elseif 
 
 
  (strncmp(engine_type, 
 
   'y' 
 
 
  ,1)) 
 
  yokedrive; 
 
   elseif 
 
 
  (strncmp(engine_type, 
 
   'r' 
 
 
  ,1)) 
 
  rockerVdrive; 
 
   elseif 
 
 
  (strncmp(engine_type, 
 
   'b' 
 
 
  ,1)) 
 
  betadrive; 
 
   else 
 
 
  fprintf( 
 
   'engine type is undefined\n' 
 
 
  ) 
 
  engine_type = 
 
   'u' 
 
 
  ; 
 
   end 
 
 
   end 
 
 
   %==============================================================