% FORCELOCS - rotate location in 3-D so specified electrodes
% match specified locations.
% CAUTION: Only for use on electrodes in
% and remaining in the upper spherical hemisphere,
% otherwise it will work improperly. Written primarily for
% adjusting all electrodes homogeneously with Cz.
%
% Usage:
% >> chanlocs = forcelocs( chanlocs ); % pop-up window mode
% >> chanlocs = forcelocs( chanlocs, loc1, loc2, ... );
% Example:
% >> chanlocs = forcelocs( chanlocs, { 0.78, 'x', 'A1' }, { 0.023, 'x', ...
% 'B1','B2','Cz' } );
%
% Inputs:
% chanlocs - EEGLAB channel structure. See help READLOCS
%
% Optional inputs:
% loc1 - cell array: { location, axis, channame1, channame2, .. }
% 'location' is new cartesian coordinate of channame1 along 'axis'
% 'axis' is either
% 'X' New x-coordinate of mean of channame1, channame2,
% etc. Used to calculate the X-Z plane angle by
% which to rotate all channels.
% Note that all rotations are to the corresponding positive
% Z-value, since theta=atan(z/x).
% 'Y' New x-coordinate of mean of channame1, channame2,
% etc.
%
% 'channame#' Name of channel(s) to be rotated, as they appear in
% chanlocs.label
% loc2 - same as loc1
%
% Outputs:
% chanlocs - updated EEGLAB channel structure.
%
%
% Author: Arnaud Delorme, CNL / Salk Institute, 15 April 2003
%
% See also: READLOCS
% Copyright (C) 2003 Arnaud Delorme, Salk Institute, arno@salk.edu
%
% This file is part of EEGLAB, see http://www.eeglab.org
% for the documentation and details.
%
% Redistribution and use in source and binary forms, with or without
% modification, are permitted provided that the following conditions are met:
%
% 1. Redistributions of source code must retain the above copyright notice,
% this list of conditions and the following disclaimer.
%
% 2. Redistributions in binary form must reproduce the above copyright notice,
% this list of conditions and the following disclaimer in the documentation
% and/or other materials provided with the distribution.
%
% THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
% AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
% IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
% ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
% LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
% CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
% SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
% INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
% CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
% ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
% THE POSSIBILITY OF SUCH DAMAGE.
function [chanlocs,options] = forcelocs( chanlocs, varargin)
NENTRY = 1; % number of lines in GUI
FIELDS = { 'X' 'Y' };
options = [];
if nargin < 1
help forcelocs;
return;
end
if nargin < 2
geom = { [0.4 1 1 0.3] };
uilist = { { 'style' 'text' 'string' 'X/Y value' 'tag' 'valstr' } ...
{ 'style' 'text' 'string' 'Choose to assign X or Y' } ...
{ 'style' 'text' 'string' 'Rotate to assign X/Y value to elec.' } ...
{ } };
for index = 1:NENTRY
tag = [ 'c' int2str(index) ];
geom = { geom{:} [0.3 1 1 0.3] };
uilist = { uilist{:},{ 'style' 'edit' 'string' fastif(index==1, '0','') }, ...
{ 'style' 'listbox' 'string' 'X (rotate X-Z plane)|Y (rotate Y-Z plane)' ...
'callback' [ 'if get(gco, ''value'') == 1,' ...
' set(findobj(gcbf, ''tag'', ''valstr''), ''string'', ''Y value'');' ...
'else set(findobj(gcbf, ''tag'', ''valstr''), ''string'', ''X value'');' ...
'end;' ] }, ...
{ 'style' 'edit' 'string' fastif(index==1, 'Cz','') 'tag' tag }, ...
{ 'style' 'pushbutton' 'string' 'Pick' ...
'callback', [ 'tmp3 = get(gcbf, ''userdata'');' ...
'[tmp1 tmp2] = pop_chansel({tmp3.labels}, ''selectionmode'', ''single'');' ...
'if ~isempty(tmp1) set(findobj(gcbf, ''tag'', ''' tag '''), ''string'', tmp2); end;' ...
'clear tmp1 tmp2;' ] } };
end
results = inputgui( geom, uilist, 'pophelp(''forcelocs'');', 'Force electrode location -- forcelocs()', chanlocs );
if length(results) == 0, return; end
options = {};
for index = 1:NENTRY
tmpi = 3*(index-1)+1;
if ~isempty(results{tmpi})
tmpchans = parsetxt(results{tmpi+2});
options = { options{:},{ str2num(results{tmpi}) FIELDS{results{tmpi+1}} tmpchans{:} }};
end
end;
else
options = varargin;
end
% scan all locations
% ------------------
channelnames = lower(strvcat({chanlocs.labels}));
for index = 1:length(options)
val = options{index}{1};
type = options{index}{2};
chans = getchans(options{index}(3:end), channelnames);
% rotate X-Z plane
% ----------------
if strcmpi(type, 'x')
curx = mean([ chanlocs(chans).X ]);
curz = mean([ chanlocs(chans).Z ]);
newx = val;
rotangle = solvesystem(curx, curz, newx);
for chanind = 1:length(chanlocs)
[chanlocs(chanind).X chanlocs(chanind).Z]= rotation(chanlocs(chanind).X, chanlocs(chanind).Z, rotangle);
end
chanlocs = convertlocs(chanlocs, 'cart2all');
end
% rotate Y-Z plane
% ----------------
if strcmpi(type, 'y')
cury = mean([ chanlocs(chans).Y ]);
curz = mean([ chanlocs(chans).Z ]);
newy = val;
rotangle = solvesystem(cury, curz, newy);
for chanind = 1:length(chanlocs)
[chanlocs(chanind).Y chanlocs(chanind).Z]= rotation(chanlocs(chanind).Y, chanlocs(chanind).Z, rotangle);
end
chanlocs = convertlocs(chanlocs, 'cart2all');
end
end
% get channel indices
% -------------------
function chanlist = getchans(chanliststr, channelnames);
chanlist = [];
for index = 1:length(chanliststr)
i = strmatch (lower(chanliststr{index}), channelnames, 'exact');
chanlist = [chanlist i];
end
% function rotate coordinates
% ---------------------------
function [X,Y] = rotation(x,y,rotangle)
X = real((x+j*y)*exp(j*rotangle));
Y = imag((x+j*y)*exp(j*rotangle));
% function solvesyst
% ------------------
function theta = solvesystem(x,y,nx)
% Original Solution
%eq(1,:) = [x -y]; res(1) = nx;
%eq(2,:) = [y x]; res(2) = sqrt(x^2+y^2-nx^2);
%sol = eq\res';
%theta = atan2(sol(2), sol(1));
% simplified solution
ny = sqrt(x^2+y^2-nx^2);
ang1 = angle(x+j*y);
ang2 = angle(nx+j*ny);
theta = ang2-ang1;
% Even simpler solution Toby 03/05/2007
% theta = atan(y/x);
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