spherror.m

含有多种ICA算法的eeglab工具箱

% spherror() - chancenter() sub function to compute minimum distance
%               of Cartesian coordinates to a sphere
%
% Author: Scott Makeig, CNL / Salk Institute, 2000

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% Copyright (C) Scott Makeig, CNL / Salk Institute, 2000
%
% This program is free software; you can redistribute it and/or modify
% it under the terms of the GNU General Public License as published by
% the Free Software Foundation; either version 2 of the License, or
% (at your option) any later version.
%
% This program is distributed in the hope that it will be useful,
% but WITHOUT ANY WARRANTY; without even the implied warranty of
% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
% GNU General Public License for more details.
%
% You should have received a copy of the GNU General Public License
% along with this program; if not, write to the Free Software
% Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

% $Log: spherror.m,v $
% Revision 1.3  2003/12/11 00:46:54  arno
% header
%
% Revision 1.2  2003/10/09 19:08:36  arno
% typo
%
% Revision 1.1  2002/04/05 17:36:45  jorn
% Initial revision
%

function wobble = spherror(center,x,y,z)
  
% 03/14/02 corrected wobble calculation -lf
  
x = x - center(1);  % center the points at (0,0,0)
y = y - center(2);
z = z - center(3);
radius = (sqrt(x.^2+y.^2+z.^2)); % distances from the center
wobble = std(radius)/mean(radius); % test if xyz values are on a sphere