bleeck@3: % method of class @signal
bleeck@3: % 
bleeck@3: %   INPUT VALUES:
bleeck@3: %  sig,attenuation
bleeck@3: % sig is the signal
bleeck@3: % attenuation is the attenuation against the lowdest possible tone
bleeck@3: % 
bleeck@3: % 
bleeck@3: %
bleeck@3: %   RETURN VALUE:
bleeck@3: %
bleeck@3: % 
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
bleeck@3: 
bleeck@3: 
bleeck@3: 
bleeck@3: 
bleeck@3: function sig=attenuate(sig,attenuation)
bleeck@3: 
bleeck@3: if attenuation==0
bleeck@3:     return
bleeck@3: end
bleeck@3: 
bleeck@3: dat=sig.werte;
bleeck@3: ma=max(dat);
bleeck@3: mi=min(dat);
bleeck@3: if -mi > ma
bleeck@3:     ma=-mi;
bleeck@3: end
bleeck@3: amphigh=ma;
bleeck@3: 
bleeck@3: amp=amphigh / power(10,-attenuation/20);
bleeck@3: if amp>0
bleeck@3:     sig=scaletomaxvalue(sig,amp);
bleeck@3: end
bleeck@3: