function act

  disp('Proof of existence for balance scale hysteresis patterns.');
  
  % See description of myact for explanation of parameters. Only the
  % parameters written in capitals are being estimated by the fmincon
  % function. 
  %              DC    di   d     nr        T     thr beta  rehearsals secs
  lowers =      [1.0; -1;  0.3;   100;      200000;  0;   0;   1; 3];
  startparams = [4.0; 0;  0.5;   100;      200000;  0;   0;   1; 15];
  uppers =      [10.0; 1;  0.7;   100;      200000;  0;   0;   1; 30];
  
  % 
  % DC/di: saliency = (diff / dc) - di
  % d: d in ACT-R baselevel calculation function (fixed at 0.5)
  % NR: number of references
  % T: "age" of the distance chunk (combination of NR and T determines baselevel)
  % thr: retrieval threshold for chunks
  % beta: beta in ACT-R baselevelcalculation function (scale-factor)
  % nR: "number of rehearsals" of retrieved distance chunks
  % 

  % Modify parameters slightly, to avoid local minima.
  startparams = adjustParams(lowers,startparams,uppers);

  startparams
  % Print parameters after modification.
  fprintf('dc:         %12.6f\n',startparams(1))
  fprintf('di:         %12.6f\n',startparams(2))
  fprintf('d:          %12.6f\n',startparams(3))
  fprintf('nr:         %12.6f\n',startparams(4))
  fprintf('t:          %12.6f\n',startparams(5))
  fprintf('threshold:  %12.6f\n',startparams(6))
  fprintf('beta:       %12.6f\n',startparams(7))
  fprintf('rehearsals: %12.6f\n',startparams(8))
  fprintf('interval:   %12.6f\n',startparams(9))

  global OBS; 
  global DIFF;
  
  % "Emperical sequence", a vector of booleans wheter or not a chunk is
  % retrieved. 
  OBS =  [ 0 0 0 1 1 1 1 1 0 0 0 ];
  % The difference between the distances from the fulcrum on the left and
  % right side for the peg with the weights.   
  DIFF = [ 1 2 3 4 5 6 5 4 3 2 1 ];

  global VERBOSE;
  global OUTFILE;

  VERBOSE = 0; % During fitting, no output.
  OUTFILE = 1; % StdOut

  global EXTBL;
  EXTBL = 1;
  
  options = optimset( 'Display' , 'iter', 'TolCon', 0, 'TolFun', 0.0001, ...
		      'TolX', 0, 'MaxFunEvals', 500 ); 

  % Find the best fit.
  [ endparams , fit, exitflag ] = fmincon('myact', startparams, [], [], [], ...
					  [], lowers, uppers, [], options); 

  VERBOSE = 1;

  myact(endparams);
  interpretExitflag(exitflag);

  % If a perfect fit was found, write the fitted model and the paramters
  % to a file which name is equal to the concatenation of the OBS vector.
  if (fit == 0.0) 
    outfilename = sprintf('%d%d%d%d%d%d%d%d%d%d%d.out',OBS);
    fprintf('Output in: %s\n',outfilename);
    
    OUTFILE = fopen(outfilename,'w');
    myact(endparams);
    fclose(OUTFILE);
  end