figure;
plotData = rand(1,59);
topoplotEEG(plotData,\'channel_locations_59ch.txt\',\'electrodes\',\'on\',\'onlymark\', [1 3 5 7 9]);

% topoplot()   - plot a topographic map of an EEG field as a 2-D
%                circular view (looking down at the top of the head) 
%                 using cointerpolation on a fine cartesian grid.
% Usage:
%        >>  topoplot(datavector,\'eloc_file\');
%        >>  topoplot(datavector,\'eloc_file\', \'Param1\',\'Value1\', ...)
% Inputs:
%    datavector = vector of values at the corresponding locations.
%   \'eloc_file\' = name of an EEG electrode position file {0 -> \'chan_file\'}
%
% Optional Parameters & Values (in any order):
%                  Param                         Value
%                \'colormap\'         -  any sized colormap
%                \'interplimits\'     - \'electrodes\' to furthest electrode
%                                     \'head\' to edge of head
%                                        {default \'head\'}
%                \'gridscale\'        -  scaling grid size {default 67}
%                \'maplimits\'        - \'absmax\' +/- the absolute-max 
%                                     \'maxmin\' scale to data range
%                                     [clim1,clim2] user-definined lo/hi
%                                        {default = \'absmax\'}
%                \'style\'            - \'straight\' colormap only
%                                     \'contour\' contour lines only
%                                     \'both\' both colormap and contour lines
%                                     \'fill\' constant color between lines
%                                     \'blank\' just head and electrodes
%                                        {default = \'both\'}
%                \'numcontour\'       - number of contour lines
%                                        {default = 6}
%                \'shading\'          - \'flat\',\'interp\'  {default = \'flat\'}
%                \'headcolor\'        - Color of head cartoon {default black}
%                \'electrodes\'       - \'on\',\'off\',\'labels\',\'numbers\'
%                \'efontsize\',\'electcolor\',\'emarker\',\'emarkersize\' - details
%
% Note: topoplot() only works when map limits are >= the max and min 
%                                     interpolated data values.
% Eloc_file format:
%         chan_number degrees radius reject_level amp_gain channel_name
%        (Angle-0 = Cz-to-Fz; C3-angle =-90; Radius at edge of image = 0.5)
%
%       For a sample eloc file:     >> topoplot(\'example\')
%
% Note: topoplot() will ignore any electrode with a position outside 
%       the head (radius > 0.5)

% Topoplot Version 2.1

% Begun by Andy Spydell, NHRC,  7-23-96
% 8-96 Revised by Colin Humphries, CNL / Salk Institute, La Jolla CA
%   -changed surf command to imagesc (faster)
%   -can now handle arbitrary scaling of electrode distances
%   -can now handle non integer angles in eloc_file
% 4-4-97 Revised again by Colin Humphries, reformat by SM
%   -added parameters
%   -changed eloc_file format
% 2-26-98 Revised by Colin
%   -changed image back to surface command
%   -added fill and blank styles
%   -removed extra background colormap entry (now use any colormap)
%   -added parameters for electrode colors and labels
%   -now each topoplot axes use the caxis command again.
%   -removed OUTPUT parameter
% 3-11-98 changed default emarkersize, improve help msg -sm

function handle = topoplot(Vl,loc_file,p1,v1,p2,v2,p3,v3,p4,v4,p5,v5,p6,v6,p7,v7,p8,v8,p9,v9,p10,v10)

% User Defined Defaults:
MAXCHANS = 256;
DEFAULT_ELOC = \'eloc64.txt\';
INTERPLIMITS = \'head\';  % head, electrodes
MAPLIMITS = \'absmax\';   % absmax, maxmin, [values]
GRID_SCALE = 67;
CONTOURNUM = 6;
STYLE = \'both\';       % both,straight,fill,contour,blank
HCOLOR = [0 0 0];
ECOLOR = [0 0 0];
CONTCOLOR = [0 0 0];
ELECTROD = \'on\';      % ON OFF LABEL
EMARKERSIZE = 6;
EFSIZE = get(0,\'DefaultAxesFontSize\');
HLINEWIDTH = 2;
EMARKER = \'.\';
SHADING = \'flat\';     % flat or interp
MARKIDX = NaN;

%%%%%%%%%%%%%%%%%%%%%%%
nargs = nargin;
if nargs < 2
  loc_file = DEFAULT_ELOC;
end
if nargs == 1
  if isstr(Vl)
    if any(strcmp(lower(Vl),{\'example\',\'demo\'}))
      fprintf([\'This is an example of an electrode location file,\n\',...
               \'an ascii file consisting of the following four columns:\n\',...
               \' channel_number degrees arc_length channel_name\n\n\',...
               \'Example:\n\',...
               \' 1               -18    .352       Fp1.\n\',...
               \' 2                18    .352       Fp2.\n\',...
               \' 5               -90    .181       C3..\n\',...
               \' 6                90    .181       C4..\n\',...
               \' 7               -90    .500       A1..\n\',...
               \' 8                90    .500       A2..\n\',...
               \' 9              -142    .231       P3..\n\',...
               \'10               142    .231       P4..\n\',...
               \'11                 0    .181       Fz..\n\',...
               \'12                 0    0          Cz..\n\',...
               \'13               180    .181       Pz..\n\n\',...
               \'The model head sphere has a diameter of 1.\n\',...
               \'The vertex (Cz) has arc length 0. Channels with arc \n\',...
               \'lengths > 0.5 are not plotted nor used for interpolation.\n\'...
               \'Zero degrees is towards the nasion. Positive angles\n\',...
               \'point to the right hemisphere; negative to the left.\n\',...
               \'Channel names should each be four chars, padded with\n\',...
               \'periods (in place of spaces).\n\'])
      return

    end
  end
end
if isempty(loc_file)
  loc_file = 0;
end
if loc_file == 0
  loc_file = DEFAULT_ELOC;
end

if nargs > 2
  if ~(round(nargs/2) == nargs/2)
    error(\'topoplot(): Odd number of inputs?\')
  end
  for i = 3:2:nargs
    Param = eval([\'p\',int2str((i-3)/2 +1)]);
    Value = eval([\'v\',int2str((i-3)/2 +1)]);
    if ~isstr(Param)
      error(\'topoplot(): Parameter must be a string\')
    end
    Param = lower(Param);
    switch lower(Param)
      case \'colormap\'
        if size(Value,2)~=3
          error(\'topoplot(): Colormap must be a n x 3 matrix\')
        end
        colormap(Value)
      case {\'interplimits\',\'headlimits\'}
        if ~isstr(Value)
          error(\'topoplot(): interplimits value must be a string\')
        end
        Value = lower(Value);
        if ~strcmp(Value,\'electrodes\') & ~strcmp(Value,\'head\')
          error(\'topoplot(): Incorrect value for interplimits\')
        end
        INTERPLIMITS = Value;
      case \'maplimits\'
        MAPLIMITS = Value;
      case \'gridscale\'
        GRID_SCALE = Value;
      case \'style\'
	STYLE = lower(Value);
      case \'numcontour\'
        CONTOURNUM = Value;
      case \'electrodes\'
	ELECTROD = lower(Value);
      case \'emarker\'
	EMARKER = Value;
      case {\'headcolor\',\'hcolor\'}
	HCOLOR = Value;
      case {\'electcolor\',\'ecolor\'}
	ECOLOR = Value;
      case {\'emarkersize\',\'emsize\'}
	EMARKERSIZE = Value;
      case {\'efontsize\',\'efsize\'}
	EFSIZE = Value;
      case \'shading\'
	SHADING = lower(Value);
	if ~any(strcmp(SHADING,{\'flat\',\'interp\'}))
	  error(\'Invalid Shading Parameter\')
    end
      case \'onlymark\'
    MARKIDX = Value;
      otherwise
	error(\'Unknown parameter.\')
    end
  end
end

[r,c] = size(Vl);
if r>1 & c>1,
  error(\'topoplot(): data should be a single vector\n\');
end
fid = fopen(loc_file);
if fid<1,
  fprintf(\'topoplot(): cannot open eloc_file (%s).\n\',loc_file);
  return
end
A = fscanf(fid,\'%d %f %f %s\',[7 MAXCHANS]);
fclose(fid);

A = A\';

if length(Vl) ~= size(A,1),
 fprintf(...
   \'topoplot(): data vector must have the same rows (%d) as eloc_file (%d)\n\',...
               length(Vl),size(A,1));
 A
 error(\'\');
end

labels = setstr(A(:,4:7));
idx = find(labels == \'.\');                       % some labels have dots
labels(idx) = setstr(abs(\' \')*ones(size(idx)));  % replace them with spaces

Th = pi/180*A(:,2);                              % convert degrees to radians
Rd = A(:,3);
ii = find(Rd <= 0.5);                     % interpolate on-head channels only
Th = Th(ii);
Rd = Rd(ii);
Vl = Vl(ii);
labels = labels(ii,:);

[x,y] = pol2cart(Th,Rd);      % transform from polar to cartesian coordinates
rmax = 0.5;

ha = gca;
cla
hold on

if ~strcmp(STYLE,\'blank\')
  % find limits for interpolation
  if strcmp(INTERPLIMITS,\'head\')
    xmin = min(-.5,min(x)); xmax = max(0.5,max(x));
    ymin = min(-.5,min(y)); ymax = max(0.5,max(y));
  else
    xmin = max(-.5,min(x)); xmax = min(0.5,max(x));
    ymin = max(-.5,min(y)); ymax = min(0.5,max(y));
  end
  
  xi = linspace(xmin,xmax,GRID_SCALE);   % x-axis description (row vector)
  yi = linspace(ymin,ymax,GRID_SCALE);   % y-axis description (row vector)
  
%   [Xi,Yi,Zi] = griddata(y,x,Vl,yi\',xi,\'invdist\'); % Interpolate data
 [Xi,Yi,Zi] = griddata(y,x,Vl,yi\',xi,\'v4\');

  
  % Take data within head
  mask = (sqrt(Xi.^2+Yi.^2) <= rmax);
  ii = find(mask == 0);
  Zi(ii) = NaN;
  
  % calculate colormap limits
  m = size(colormap,1);
  if isstr(MAPLIMITS)
    if strcmp(MAPLIMITS,\'absmax\')
      amin = -max(max(abs(Zi)));
      amax = max(max(abs(Zi)));
    elseif strcmp(MAPLIMITS,\'maxmin\')
      amin = min(min(Zi));
      amax = max(max(Zi));
    end
  else
    amin = MAPLIMITS(1);
    amax = MAPLIMITS(2);
  end
  delta = xi(2)-xi(1); % length of grid entry
  
  % Draw topoplot on head
  if strcmp(STYLE,\'contour\')
    contour(Xi,Yi,Zi,CONTOURNUM,\'k\');
  elseif strcmp(STYLE,\'both\')
    if sum(isnan(MARKIDX))
        surface(Xi-delta/2,Yi-delta/2,zeros(size(Zi)),Zi,\'EdgeColor\',\'none\',...
        \'FaceColor\',SHADING);
    %     colorbar;
        contour(Xi,Yi,Zi,CONTOURNUM,\'k\');
    end
  elseif strcmp(STYLE,\'straight\')
    surface(Xi-delta/2,Yi-delta/2,zeros(size(Zi)),Zi,\'EdgeColor\',\'none\',...
	\'FaceColor\',SHADING);
%     colorbar
  elseif strcmp(STYLE,\'fill\')
    contourf(Xi,Yi,Zi,CONTOURNUM,\'k\');
  else
    error(\'Invalid style\')
  end
  caxis([amin amax]) % set coloraxis
end

set(ha,\'Xlim\',[-rmax*1.3 rmax*1.3],\'Ylim\',[-rmax*1.3 rmax*1.3])

% %%% Draw Head %%%%
l = 0:2*pi/100:2*pi;
basex = .18*rmax;  
tip = rmax*1.15; base = rmax-.004;
EarX = [.497 .510 .518 .5299 .5419 .54 .547 .532 .510 .489];
EarY = [.0555 .0775 .0783 .0746 .0555 -.0055 -.0932 -.1313 -.1384 -.1199];

% Plot Head, Ears, Nose
plot(cos(l).*rmax,sin(l).*rmax,...
    \'color\',HCOLOR,\'Linestyle\',\'-\',\'LineWidth\',HLINEWIDTH);

plot([.18*rmax;0;-.18*rmax],[base;tip;base],...
    \'Color\',HCOLOR,\'LineWidth\',HLINEWIDTH);
   
plot(EarX,EarY,\'color\',HCOLOR,\'LineWidth\',HLINEWIDTH)
plot(-EarX,EarY,\'color\',HCOLOR,\'LineWidth\',HLINEWIDTH)   

% Plot Electrodes
if strcmp(ELECTROD,\'on\') 
    if sum(isnan(MARKIDX))
        hp2 = plot(y,x,EMARKER,\'Color\',ECOLOR,\'markersize\',EMARKERSIZE);
    else
        markedIdx = false(numel(y),1);
        markedIdx(MARKIDX) = true;
        hp2 = plot(y(~markedIdx),x(~markedIdx),EMARKER,\'Color\',ECOLOR,\'markersize\',EMARKERSIZE);
        hp2 = plot(y(markedIdx),x(markedIdx),EMARKER,\'Color\',\'r\',\'markersize\',3*EMARKERSIZE);
    end
elseif strcmp(ELECTROD,\'labels\')
  for i = 1:size(labels,1)
    text(y(i),x(i),labels(i,:),\'HorizontalAlignment\',\'center\',...
	\'VerticalAlignment\',\'middle\',\'Color\',ECOLOR,...
	\'FontSize\',EFSIZE)
  end
elseif strcmp(ELECTROD,\'numbers\')
whos y x 
  for i = 1:size(labels,1)
    text(y(i),x(i),int2str(i),\'HorizontalAlignment\',\'center\',...
	\'VerticalAlignment\',\'middle\',\'Color\',ECOLOR,...
	\'FontSize\',EFSIZE)
  end
end

hold off
axis off