view aim-mat/tools/@signal/leakyintegrator.m @ 0:74dedb26614d

Initial checkin of AIM-MAT version 1.5 (6.4.2011).

% (c) 2003-2008, University of Cambridge, Medical Research Council 
% http://www.pdn.cam.ac.uk/cnbh/aim2006
% $Date: 2008-06-10 18:00:16 +0100 (Tue, 10 Jun 2008) $
% $Revision: 585 $
%

function nvals=leakyintegrator(sig,lowpass_cutoff_frequency,order)


time_constant=1/(2.*pi.*lowpass_cutoff_frequency);
sr=getsr(sig);
vals=getvalues(sig);
b=exp(-1/(sr.*time_constant));
gain=1./(1-b);


nvals=zeros(size(vals));
for dothis=1:order
	xn_1=0;
	yn_1=0;
    for i=1:length(vals)
        xn=vals(i);
        yn= xn + b*yn_1 ;
        xn_1=xn;
        yn_1=yn;
        nvals(i)=yn;
    end
    vals=nvals./gain;
end

nvals=vals;