%?This?demo?script?shows?how?to?perform?SFA?on?user-defined?function
%?spaces.?The?user?has?to?overwrite?the?functions?EXPANSION?and
%?XP_DIM.?In?this?example?the?two?functions?are?located?in?the
%?subdirectory?sfa_tk/demo/expansion_demo/?.?Further?information?can?be
%?found?on?the?online?documentation.

%?init?graphics
figure;?clf;?set（gcf?‘Position‘?[618?173?575?727]）;

%?!!!?The?following?lines?installs?the?user-defined?EXPANSION?and?XP_DIM
%?functions?defined?in?the?expansion_demo/?subdirectory.
%?You?might?need?to?change?this?line?if?you?don‘t?start?the?script?from
%?the?demo/?directory.
addpath?expansion_demo/

%?create?the?input?signal
T?=?5000;
t?=?linspace（0?2*pi?T）;

x1?=?-sin（t）+2*cos（11*t）.^4;
x2?=?cos（11*t）;
x?=?[x1;?x2]‘;

%?show?the?input?signal
clf;?subplot（311）;?plot（x）;
title（‘input?signals‘）;

%?linear?SFA?won‘t?be?able?to?recover?the?slowest?source?signal?sin（t）
%?since?it?is?nonlinearly?mixed
fprintf（‘\nLINEAR?SFA\n\n‘）;
y?=?sfa1（x）;
subplot（312）;?plot（y（:1））;
title（‘signal?exctracted?by?linear?SFA‘）;

%?the?user-defined?expansion?function?contains?a?to-the-fourth?nonlinearity
%?which?allows?SFA?to?reconstruct?the?slowest?source?signal?sin（t）.
%?if?the?user-defined?functions?are?really?used?appropriate?messages
%?should?have?been?printed?on?the?screen.
fprintf（‘\nEXPANDED?SFA\n\n‘）;
y?=?sfa2（x）;
subplot（313）;?plot（y（:1））;
title（[‘signal?exctracted?by?nonlinear?SFA?in?a‘?...
??????‘?user-defined?function?space‘]）;

%?!!!?Remove?the?user-defined?EXPANSION?and?XP_DIM?functions?defined?in
%?the?expansion_demo/?subdirectory.?You?might?need?to?change?this?line
%?if?you?don‘t?start?the?script?from?the?demo/?directory
rmpath?expansion_demo/