annotate aim-mat/tools/@signal/generateamnoise.m @ 0:74dedb26614d

Initial checkin of AIM-MAT version 1.5 (6.4.2011).
author tomwalters
date Fri, 20 May 2011 12:32:31 +0100
parents
children 20ada0af3d7d
rev   line source
tomwalters@0 1 % method of class @signal
tomwalters@0 2 % function sig=genbandpassnoise(sig,varargin)
tomwalters@0 3 % INPUT VALUES:
tomwalters@0 4 % sig: @signal with length and samplerate
tomwalters@0 5 % RETURN VALUE:
tomwalters@0 6 % sig: @signal
tomwalters@0 7 %
tomwalters@0 8 % (c) 2003-2008, University of Cambridge, Medical Research Council
tomwalters@0 9 % Maintained by Tom Walters (tcw24@cam.ac.uk), written by Stefan Bleeck (stefan@bleeck.de)
tomwalters@0 10 % http://www.pdn.cam.ac.uk/cnbh/aim2006
tomwalters@0 11 % $Date: 2008-06-10 18:00:16 +0100 (Tue, 10 Jun 2008) $
tomwalters@0 12 % $Revision: 585 $
tomwalters@0 13
tomwalters@0 14 function sig=generateAMnoise(sig,fre,modgrad)
tomwalters@0 15
tomwalters@0 16 len=getlength(sig);
tomwalters@0 17 sr=getsr(sig);
tomwalters@0 18
tomwalters@0 19 % generate white noise:
tomwalters@0 20 vals=getvalues(sig);
tomwalters@0 21 vals=rand(size(vals)).*2-1;
tomwalters@0 22 sig=setvalues(sig,vals);
tomwalters@0 23
tomwalters@0 24 envelope=generatesinus(sig,fre,1,0);
tomwalters@0 25 envelope=(envelope+1)/2;
tomwalters@0 26
tomwalters@0 27 sig=sig*envelope;
tomwalters@0 28
tomwalters@0 29
tomwalters@0 30 sig=setname(sig,sprintf('AM noise Frequency %4.1f Hz',fre));
tomwalters@0 31
tomwalters@0 32 return