mfbox_sompnl.m

toolbox for spm 5 for data, model free analysis

function [S,P]=mfbox_sompnl(X,varargin)
%mfbox_sompnl - pnl ica algo using a som
%
% [S,P]=mfbox_sompnl(X[,argID,value[...]]);
%
% Copyright by Peter Gruber
% Signal Processing & Information Theory group
% Institute of Biophysics, University of Regensburg, Germany
% Homepage: http://research.fabian.theis.name
%           http://www-aglang.uni-regensburg.de
%
% This file is free software, subject to the 
% GNU GENERAL PUBLIC LICENSE, see gpl.txt

error(nargchk(1,Inf,nargin));

numofic = Inf;
nonlintype = 'polynomial';
verbose = 0;
plotting = 0;
gridsize = 10;

l = nargin-1;
for i=1:2:l
    op = varargin{i};
    pa = varargin{i+1};
    switch lower(op)
        case 'numofic'
            numofic = pa;
        case 'gridsize'
            gridsize = pa;
        case 'nonlintype'
            nonlintype = pa;
        case 'verbose'
            p = find(strcmp(pa,onoff));
            verbose = p(1)-1;
        case 'plotting'
            p = find(strcmp(pa,onoff));
            plotting = p(1)-1;
        otherwise
            error('Unknown parameter %s!\n',cmd);
    end
end

sX = size(X);

numofic = min(sX(1),numofic);
gridsize = max(gridsize,10);

grid = mfbox_mkgrid(ones(1,numofic)*(2*gridsize+1))-gridsize;

switch nonlintype
    case 'polynomial'
        A = eye(numofic,sX(1));
        B = repmat([0,1,zeros(1,degree-2)],numofic,1);
        C = degree;
    case 'piecelin'
        A = eye(numofic,sX(1));
        m = max(abs(X(:)))
        B = repmat([1,zeros(1,C-1)],numofic,1);
        C = repmat(linspace(-m,m,degree),numofic,1);
end

while (i<maxiter)
    mapgrid = domap(grid,A,nonlintype,B,C);

    %calculate adjustment

    [dA,dB,dC] = findmingradient(mapgrid,newgrid,A,nonlintype,B,C);
    A = A+dA;
    B = B+dB;
    C = C+dC;
end

return

function r=lrfunc(m,d)
if (d==1), r = linspace(1,0,m);
elseif (d==Inf), r = exp(1:m)/exp(1);
else r = (1:m).^(-d);
end

return

function d=expdist(d,rho)
d = exp((-d.^2)/(2*rho^2));

return

function d=chardist(d,rho)
d = 1*(abs(d)<rho);

return

function d=quaddist(d,rho)
d = max(0,1-(rho-d).^2);

return

function d=lindist(d,rho)
d = max(0,1-abs(rho-d));

return