function nnd12vl(cmd,arg1)
%NND12VL Variable learning rate backpropagation demonstration.
%
%	This demonstration requires the Neural Network Toolbox.

% First Version, 8-31-95.

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

% CONSTANTS
me = 'nnd12vl';
max_t = 0.5;
w_max = 10;
p_max = 2;
circle_size = 6;
mc = 0.8;
inc = 1.05;
dec = 0.7;
er = 1.04;
lr = 14;

% FLAGS
change_func = 0;

% 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
  lr_bar = H(3);              % learning rate slider bar
  lr_text = H(4);             % learning rate text
  inc_bar = H(5);             % learning rate increase slider bar
  inc_text = H(6);            % learning rate increase text
  dec_bar = H(7);             % learning rate decrease slider bar
  dec_text = H(8);            % learning rate decrease text
  cont_axis = H(9);           % error contour axis
  cont_ptr = H(10);           % pointer to error contour handles
  variables = H(11:14);       % variable name texts
  radios = H(15:17);          % radio buttons
  option_ptr = H(18);         % index of active radio
  path_ptr = H(19);           % pointer to training path handles
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)

  % CHECK FOR NNT
  if ~nntexist(me), return, end

  % CONSTANTS
  W1 = [10; 10];
  b1 = [-5;5];
  W2 = [1 1];
  b2 = [-1];
  P = -2:0.1:2;
  T = logsig(W2*logsig(W1*P,b1),b2);

  % NEW DEMO FIGURE
  fig = nndemof2(me,'DESIGN','Variable LR Backpropagation','','Chapter 12');
  set(fig, ...
    'windowbuttondownfcn',nncallbk(me,'down'), ...
    'BackingStore','off',...
    'nextplot','add');
  H = get(fig,'userdata');
  fig_axis = H(1);
  desc_text = H(2);

  % ICON
  nndicon(12,458,363,'shadow')

  % NETWORK POSITIONS
  x1 = 40;     % input
  x2 = x1+90;  % 1st layer sum
  x3 = x2+40;  % 1st layer transfer function
  x4 = x3+100; % 2nd layer sum
  x5 = x4+40;  % 2nd layer transfer function
  x6 = x5+50;  % output
  y1 = 330;    % top neuron
  y2 = y1-35;  % input & output neuron
  y3 = y1-70;  % bottom neuron
  sz = 15;     % size of icons
  wx = 55;     % weight vertical offset (from 1st layer)
  wy = 40;     % weight horizontal offset (from middle)

  % NETWORK INPUT
  nndtext(x1-10,y2,'p');
  plot([x2-sz x1 x2-sz],[y1 y2 y3],'linewidth',2,'color',nnred);

  % TOP NEURON
  plot([x2 x2 x3],[y1-sz*2 y1 y1],'linewidth',2,'color',nnred);
  nndsicon('sum',x2,y1,sz)
  nndsicon('logsig',x3,y1,sz)
  var1 = nndtext(x2-wx,y2+wy,'W1(1,1)');
  set(var1,'color',[1 1 1])
  nndtext(x2+2,y1-sz*2-13,'1');
  var2 = nndtext(x2+10,y1-sz*2,'b1(1)','left');

  % BOTTOM NEURON
  plot([x2 x2 x3],[y3-sz*2 y3 y3],'linewidth',2,'color',nnred);
  nndsicon('sum',x2,y3,sz)
  nndsicon('logsig',x3,y3,sz)
  nndtext(x2-wx,y2-wy,'W1(2,1)');
  nndtext(x2+2,y3-sz*2-13,'1');
  var3 = nndtext(x2+10,y3-sz*2,'b1(2)','left');

  % OUTPUT NEURON
  plot([x3+sz x4-10 x3+sz],[y1 y2 y3],'linewidth',2,'color',nnred);
  plot([x4 x4 x6],[y2-sz*2 y2 y2],'linewidth',2,'color',nnred);
  plot([x6-10 x6 x6-10],[y2-7 y2 y2+7],'linewidth',2,'color',nnred);
  nndsicon('sum',x4,y2,sz)
  nndsicon('logsig',x5,y2,sz);
  var4 = nndtext(x3+wx,y2+wy,'W2(1,1)');
  set(var4,'color',[1 1 1])
  nndtext(x3+wx,y2-wy,'W2(1,2)');
  nndtext(x4+2,y2-sz*2-13,'1');
  nndtext(x4+10,y2-sz*2,'b2','left');
  nndtext(x5+sz+5,y2+8,'a2','left');

  % LEARNING RATE SLIDER BAR
  x = 20;
  y = 170;
  text(x,y,'Initial Learning Rate:',...
    'color',nndkblue,...
    'fontw','bold',...
    'fontsize',12,...
    'horizontalalignment','left')
  lr_text = text(x+160,y,num2str(lr),...
    'color',nndkblue,...
    'fontw','bold',...
    'fontsize',12,...
    'horizontalalignment','right');
  text(x,y-38,'0.0',...
    'color',nndkblue,...
    'fontw','bold',...
    'fontsize',12,...
    'horizontalalignment','left')
  text(x+160,y-38,'20.0',...
    'color',nndkblue,...
    'fontw','bold',...
    'fontsize',12,...
    'horizontalalignment','right');
  lr_bar = uicontrol(...
    'units','points',...
    'position',[x y-25 160 16],...
    'style','slider',...
    'backg',nnltgray,...
    'callback',[me '(''lr'')'],...
    'min',0,...
    'max',20,...
    'value',lr);

  % INCREASE RATIO SLIDER BAR
  x = 20;
  y = 110;
  text(x,y,'Increase Rate:',...
    'color',nndkblue,...
    'fontw','bold',...
    'fontsize',12,...
    'horizontalalignment','left')
  inc_text = text(x+160,y,num2str(inc),...
    'color',nndkblue,...
    'fontw','bold',...
    'fontsize',12,...
    'horizontalalignment','right');
  text(x,y-38,'1.00',...
    'color',nndkblue,...
    'fontw','bold',...
    'fontsize',12,...
    'horizontalalignment','left')
  text(x+160,y-38,'1.20',...
    'color',nndkblue,...
    'fontw','bold',...
    'fontsize',12,...
    'horizontalalignment','right');
  inc_bar = uicontrol(...
    'units','points',...
    'position',[x y-25 160 16],...
    'style','slider',...
    'backg',nnltgray,...
    'callback',[me '(''inc'')'],...
    'min',1,...
    'max',1.2,...
    'value',inc);

  % DECREASE RATIO SLIDER BAR
  x = 20;
  y = 50;
  text(x,y,'Decrease Rate:',...
    'color',nndkblue,...
    'fontw','bold',...
    'fontsize',12,...
    'horizontalalignment','left')
  dec_text = text(x+160,y,num2str(dec),...
    'color',nndkblue,...
    'fontw','bold',...
    'fontsize',12,...
    'horizontalalignment','right');
  text(x,y-38,'0.50',...
    'color',nndkblue,...
    'fontw','bold',...
    'fontsize',12,...
    'horizontalalignment','left')
  text(x+160,y-38,'1.00',...
    'color',nndkblue,...
    'fontw','bold',...
    'fontsize',12,...
    'horizontalalignment','right');
  dec_bar = uicontrol(...
    'units','points',...
    'position',[x y-25 160 16],...
    'style','slider',...
    'backg',nnltgray,...
    'callback',[me '(''dec'')'],...
    'min',0.5,...
    'max',1.0,...
    'value',dec);

  % RADIO BUTTONS
  option = 1;
  radio1 = uicontrol(...
    'units','points',...
    'position',[20 180 130 20],...
    'style','radio',...
    'string','W1(1,1), W2(1,1)',...
    'back',nnltgray,...
    'callback',[me '(''radio'',1)'],...
    'value',1);
  radio2 = uicontrol(...
    'units','points',...
    'position',[155 180 115 20],...
    'style','radio',...
    'string','W1(1,1), b1(1)',...
    'back',nnltgray,...
    'callback',[me '(''radio'',2)']);
  radio3 = uicontrol(...
    'units','points',...
    'position',[270 180 105 20],...
    'style','radio',...
    'string','b1(1), b1(2)',...
    'back',nnltgray,...
    'callback',[me '(''radio'',3)']);

  % ERROR SURFACE
  load nndbp1

  cont_axis = nnsfo('a2','',v1,v2,'');
  set(cont_axis, ...
    'units','points',...
    'position',[230 40 130 130],...
    'color',nnltyell,...
    'xlim',range1,...
    'ylim',range2,...
    'colororder',[0 0 0])
  [dummy,cont_h] = contour(x2,y2,E2,levels);
  set(cont_h,'erasemode','none');
  plot3(range1([1 2 2 1 1]),range2([1 1 2 2 1]),1000*ones(1,5),...
    'color',nndkblue);
  cont_h2 = plot(optx,opty,'+','color',nnred);
  cont_h = [cont_h; cont_h2];
  view(2)