--- a
+++ b/code/preprocessing/EEG/fastica/demosig.m
@@ -0,0 +1,32 @@
+function [sig,mixedsig]=demosig();
+%
+% function [sig,mixedsig]=demosig();
+% 
+% Returns artificially generated test signals, sig, and mixed
+% signals, mixedsig. Signals are row vectors of
+% matrices. Input mixedsig to FastICA to see how it works.
+
+% @(#)$Id$
+
+%create source signals (independent components)
+N=500; %data size
+
+v=[0:N-1];
+sig=[];
+sig(1,:)=sin(v/2); %sinusoid
+sig(2,:)=((rem(v,23)-11)/9).^5; %funny curve
+sig(3,:)=((rem(v,27)-13)/9); %saw-tooth
+sig(4,:)=((rand(1,N)<.5)*2-1).*log(rand(1,N)); %impulsive noise
+
+for t=1:4
+sig(t,:)=sig(t,:)/std(sig(t,:));
+end
+
+%remove mean (not really necessary)
+
+[sig mean]=remmean(sig);
+
+%create mixtures
+
+Aorig=rand(size(sig,1));
+mixedsig=(Aorig*sig);