function nnd7sh(cmd,arg1,arg2,arg3)
%NND7SH Supervised Hebb demonstration.

%==================================================================

% CONSTANTS
me = 'nnd7sh';
p_x = 5; % pattern horizontal size
p_y = 6; % pattern vertical size

% DEFAULTS
if nargin == 0, cmd = ''; else cmd = lower(cmd); end

% FIND WINDOW IF IT EXISTS
fig = nnfgflag(me);
if length(get(fig,'children')) == 0, fig = 0; end

% GET WINDOW DATA IF IT EXISTS
if fig
  H = get(fig,'userdata');
  fig_axis = H(1);            % window axis
  desc_text = H(2);           % handle to first line of text sequence
  pattern = H(3:5);           % pattern axes 1-3
  tp_axis = H(6);             % test pattern
  rp_axis = H(7);             % response pattern
  P_ptr = H(8);               % handle to pattern matrix P
  p_ptr = H(9);               % handle to test pattern
  w_ptr = H(10);              % handle to weight matrix W
  rule1 = H(11);              % handle to first radio button
  rule2 = H(12);              % handle to second radio button
end

%==================================================================
% Activate the window.
%
% ME() or ME('')
%==================================================================

if strcmp(cmd,'')
  if fig
    figure(fig)
    set(fig,'visible','on')
  else
    feval(me,'init')
  end

%==================================================================
% Close the window.
%
% ME() or ME('')
%==================================================================

elseif strcmp(cmd,'close') & (fig)
  delete(fig)

%==================================================================
% Initialize the window.
%
% ME('init')
%==================================================================

elseif strcmp(cmd,'init') & (~fig)

  % STANDARD DEMO FIGURE
  fig = nndemof2(me,'DESIGN','Supervised Hebb','','Chapter 7');
  set(fig, ...
    'windowbuttondownfcn',nncallbk(me,'down'), ...
    'BackingStore','off',...
    'nextplot','add');
  H = get(fig,'userdata');
  fig_axis = H(1);
  desc_text = H(2);

  % ICON
  nndicon(7,458,363,'shadow')
  
  % ORIGONAL PATTERNS
  p1 = [0 1 1 1 1 0 ...
        1 0 0 0 0 1 ...
        1 0 0 0 0 1 ...
        1 0 0 0 0 1 ...
        0 1 1 1 1 0]';
  p2 = [0 0 0 0 0 0 ...
        1 0 0 0 0 0 ...
        1 1 1 1 1 1 ...
        0 0 0 0 0 0 ...
        0 0 0 0 0 0]';
  p3 = [1 0 0 0 0 0 ...
        1 0 0 1 1 1 ...
        1 0 0 1 0 1 ...
        1 0 0 1 0 1  ...
        0 1 1 0 0 1]';
  P = [p1 p2 p3]*2-1;
  p  = p1*2-1;

  % WEIGHTS & OUTPUTS
  w = P*P';
  a = w*p;

  % PATTERN AXES
  pattern = zeros(1,5);
  ltyell = nnltyell;
  for k=1:5
    if k < 4
      title = sprintf('Pattern %g',k);
      pos = [25+115*(k-1) 230 100 100];
      pp = reshape(P(:,k),p_y,p_x);
      color = nngreen;
    elseif k == 4
      title = 'Test Pattern';
      pos = [25 20 160 160];
      pp = reshape(p,p_y,p_x);
      color = nndkgray;
    else
      title = 'Response Pattern';
      pos = [195 20 160 160];
      pp = reshape(a,p_y,p_x);
      color = nnred;
    end
    pattern(k) = nnsfo('a2',title,'','');
    set(pattern(k), ...
      'units','points',...
      'position',pos,...
      'color',nnltyell,...
      'xlim',[0 p_x], ...
      'ylim',[0 p_y],...
      'ydir','reverse')
    axis('off')
    pattern_h = zeros(p_y,p_x);
    box_x = [0 1 1 0 0];
    box_y = [0 0 1 1 0];
    for i=1:p_x, for j=1:p_y
      if pp(j,i) >= 0
        pattern_h(i,j) = fill(box_x+i-1,box_y+j-1,color,...
          'edgecolor',nndkblue,...
          'erasemode','none');
      else
        pattern_h(i,j) = fill(box_x+i-1,box_y+j-1,ltyell,...
          'edgecolor',nndkblue,...
          'erasemode','none');
      end
    end, end
    set(pattern(k),'userdata',pattern_h);
  end
  
  % WEIGHT RULE BUTTONS
  drawnow   % Let everything else appear before buttons 
  rule1 = uicontrol(...
    'units','points',...
    'position',[395 190 90 20],...
    'style','radio',...
    'string','Hebb',...
    'backg',nnltgray,...
    'callback',[me '(''rule'',1)'],...
    'value',1);
  rule2 = uicontrol(...
    'units','points',...
    'position',[395 170 90 20],...
    'style','radio',...
    'string','Psuedoinverse',...
    'backg',nnltgray,...
    'callback',[me '(''rule'',2)']);

  % BUTTONS
  if (exist('hintonw'))
    uicontrol(...
      'units','points',...
      'position',[410 140 60 20],...
      'string','Weights',...
      'callback',[me '(''weights'')'])
  end
  uicontrol(...
    'units','points',...
    'position',[410 110 60 20],...
    'string','Contents',...
    'callback','nndtoc')
  uicontrol(...
    'units','points',...
    'position',[410 80 60 20],...
    'string','Close',...
    'callback','delete(gcf)')

  % DATA POINTERS
  P_ptr = nnsfo('data'); set(P_ptr,'userdata',P);
  p_ptr = nnsfo('data'); set(p_ptr,'userdata',p);
  w_ptr = nnsfo('data'); set(w_ptr,'userdata',w);
  
  % SAVE WINDOW DATA AND LOCK
  H = [fig_axis desc_text pattern P_ptr p_ptr w_ptr rule1 rule2];
  set(fig,'userdata',H,'nextplot','new','color',nnltgray)

  % INSTRUCTION TEXT
  feval(me,'instr');

  nnchkfs;

%==================================================================
% Display the instructions.
%
% ME('instr')
%==================================================================

elseif strcmp(cmd,'instr') & (fig)
  nnsettxt(desc_text,...
    'Click on the green',...
    'grids to define target.',...
    'patterns. Click on the',...
    'gray grid to define',...
    'a test pattern.',...
    '',...
    'Select the rule to',...
    'calculate the network',...
    'weights below:')

%==================================================================
% Show weights.
%
% ME('weights')
%==================================================================

elseif strcmp(cmd,'weights') & (fig) & (nargin == 1)

  % GET DATA
  w = get(w_ptr,'userdata');

  f = figure;
  feval('hintonw',w);
  axis('equal');
  set(f,'name','Network Weights')
  t = get(gca,'title');
  set(t,'string','Green = Positive, Red = Negative')

%==================================================================
% Respond to mouse down.
%
% ME('down')
%==================================================================

elseif strcmp(cmd,'down') & (fig) & (nargin == 1)

  set(fig,'nextplot','add')
  for i=1:3
    [in,x,y] = nnaxclik(pattern(i));
    if in
      feval(me,'down',x,y,i);
      break
    end
  end
  [in,x,y] = nnaxclik(tp_axis);
  if in
    feval(me,'down',x,y);
  end
  set(fig,'nextplot','new')

%==================================================================
% Respond to mouse down in pattern 1-3.
%
% ME('down',x,y,i)
%==================================================================

elseif strcmp(cmd,'down') & (fig) & (nargin == 4)
  
  % GET DATA
  x = floor(arg1)+1;
  y = floor(arg2)+1;
  i = arg3;
  green = nngreen;
  ltyell = nnltyell;
  red = nnred;
  P = get(P_ptr,'userdata');
  p = get(p_ptr,'userdata');
  squares = get(pattern(i),'userdata');
  rp_squares = get(rp_axis,'userdata');
  rule = get(rule2,'value')+1;
  
  % TOGGLE SQUARE
  ind = (x-1)*p_y+y;
  P(ind,i) = -P(ind,i);
  if P(ind,i) > 0
    set(squares(x,y),'facecolor',green);
  else
    set(squares(x,y),'facecolor',ltyell);
  end
  drawnow

  % UPDATE WEIGHTS
  if rule == 1
    w = P*P';
  else
    w = P*inv(P'*P)*P';
  end

  % STORE DATA
  set(P_ptr,'userdata',P);
  set(w_ptr,'userdata',w);

  % UPDATE OUTPUTS
  feval(me,'update')

%==================================================================
% Respond to mouse down in test pattern.
%
% ME('down',x,y)
%==================================================================

elseif strcmp(cmd,'down') & (fig) & (nargin == 3)
  
  % GET DATA
  x = floor(arg1)+1;
  y = floor(arg2)+1;
  dkgray = nndkgray;
  ltyell = nnltyell;
  tp_squares = get(tp_axis,'userdata');
  rp_squares = get(rp_axis,'userdata');
  p = get(p_ptr,'userdata');
  w = get(w_ptr,'userdata');

  % TOGGLE SQUARE
  ind = (x-1)*p_y+y;
  p(ind) = -p(ind);
  if p(ind) > 0
    set(tp_squares(x,y),'facecolor',dkgray);
  else
    set(tp_squares(x,y),'facecolor',ltyell);
  end
  drawnow

  % STORE DATA
  set(p_ptr,'userdata',p);
  
  % UPDATE OUTPUTS
  feval(me,'update')

%==================================================================
% Set weight rule.
%
% ME('rule',i)
%==================================================================

elseif strcmp(cmd,'rule') & (fig) & (nargin == 2)
  
  % SET RADIO BUTTONS
  if arg1 == 1
    set(rule1,'value',1)
    set(rule2,'value',0)
  else
    set(rule1,'value',0)
    set(rule2,'value',2)
  end

  % GET DATA
  P = get(P_ptr,'userdata');

  % UPDATE WEIGHTS
  if arg1 == 1
    w = P*P';
  else
    w = P*inv(P'*P)*P';
  end

  % STORE DATA
  set(w_ptr,'userdata',w)

  % UPDATE OUTPUTS
  feval(me,'update')

%==================================================================
% Update response pattern.
%
% ME('update')
%==================================================================

elseif strcmp(cmd,'update') & (fig)

  % GET DATA
  red = nnred;
  ltyell = nnltyell;
  p = get(p_ptr,'userdata');
  w = get(w_ptr,'userdata');
  rp_squares = get(rp_axis,'userdata');

  % UPDATE OUTPUTS
  a = w*p;
  a = reshape(a,p_y,p_x);
  for i=1:p_x, for j=1:p_y
    if a(j,i) > 0
      set(rp_squares(i,j),'facecolor',red)
    else
      set(rp_squares(i,j),'facecolor',ltyell)
    end
  end, end

%==================================================================
end