bleeck@3: % This external file is included as part of the 'aim-mat' distribution package
bleeck@3: % (c) 2011, University of Southampton
bleeck@3: % Maintained by Stefan Bleeck (bleeck@gmail.com)
bleeck@3: % download of current version is on the soundsoftware site: 
bleeck@3: % http://code.soundsoftware.ac.uk/projects/aimmat
bleeck@3: % documentation and everything is on http://www.acousticscale.org
tomwalters@0: 
tomwalters@0: 
tomwalters@0: function sig=toshio_lowpass(sig,cutoff,order)
tomwalters@0: 
tomwalters@0: %variable: order, is not used,
tomwalters@0: % a 2nd order filter is assumed,
tomwalters@0: % taken from Irino code: CalNAPghll.m
tomwalters@0: 
tomwalters@0: 
tomwalters@0: if nargin<2
tomwalters@0:     order=1;
tomwalters@0: end
tomwalters@0: 
tomwalters@0: 
tomwalters@0: sr=getsr(sig);
tomwalters@0: vals=getvalues(sig);
tomwalters@0: 
tomwalters@0: [bzLP apLP] = butter(1,cutoff/(sr/2));
tomwalters@0: bzLP2 = [bzLP(1)^2,  2*bzLP(1)*bzLP(2), bzLP(2)^2]; 
tomwalters@0: apLP2 = [apLP(1)^2,  2*apLP(1)*apLP(2), apLP(2)^2]; 
tomwalters@0: 
tomwalters@0: sig_len = length(vals);
tomwalters@0: 
tomwalters@0: filt_vals(1:sig_len) = filter(bzLP2,apLP2,vals);
tomwalters@0: vals=filt_vals;
tomwalters@0: 
tomwalters@0: 
tomwalters@0: 
tomwalters@0: sig=setvalues(sig,vals);
tomwalters@0: