multiplotER and Neuromag data

Stephan Moratti moratti at MED.UCM.ES
Wed Feb 24 11:23:29 CET 2010

Hola Gianpaolo,

I had the same problem as you. The probel lies in the ft_prepare_layout.m 
function. It calculates the minimum distance between sensors. As the 
neuromag sensor has different types of sensors, the layout puts the 3 
different sensors at the same place. So calculating the min(d(:)) results in 0 
values. Please find below the modified subfunction sens2lay that is located in 
ft_prepare_layout.m that prevents this error. With that, the topoplots (and 
multiplots) should work out. Maybe this error can be prevented in a more 
elegant way that I did.



% convert 3D electrode positions into 2D layout
function lay = sens2lay(sens, rz, method, style)

fprintf('creating layout for %s system\n', senstype(sens));
% apply rotation
if isempty(rz)
  switch senstype(sens)
{'ctf151', 'ctf275', 'bti148', 'bti248', 'ctf151_planar', 'ctf275_planar', 'bti148_pla
nar', 'bti248_planar'}
      rz = 90;
    case {'neuromag122', 'neuromag306'}
      rz = 0;
    case 'electrode'
      rz = 90;
      rz = 0;
sens.pnt = warp_apply(rotate([0 0 rz]), sens.pnt, 'homogenous');

% use helper function for 3D layout
[pnt, label] = channelposition(sens);

if strcmpi(style, '3d')
  lay.pos   = pnt;
  lay.label = label;
  if strcmp(senstype(sens),'neuromag306') %this is to prevent distance of 0
      prj = elproj(pnt(1:102,:), method);
    prj = elproj(pnt, method);
  d = dist(prj');
  d(find(eye(size(d)))) = inf;
  mindist = min(d(:));
  % this is to fix the planar layouts, which cannot be plotted anyway
  if n>1  %this is to prevent confusion when lab happens to be a row array
    prj = repmat(prj, n, 1);
  X = prj(:,1);
  Y = prj(:,2);
  Width  = ones(size(X)) * mindist * 0.8;
  Height = ones(size(X)) * mindist * 0.6;
  lay.pos    = [X Y];
  lay.width  = Width;
  lay.height = Height;
  lay.label  = label;

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