tomwalters@0: % method of class @signal
tomwalters@0: % function sigresult=smooth(org_sig,sigma)
tomwalters@0: %   INPUT VALUES:
tomwalters@0: %       org_sig:       orgiginal @signal
tomwalters@0: %       sigma:         smooth width
tomwalters@0: %       type:          'gauss'  gauss average, sigma is sigma of gauss function (default)
tomwalters@0: %                      'rect'   rectangle window,  width = 2*sigma+1 
tomwalters@0: %                               mirrow signal at border
tomwalters@0: %                       
tomwalters@0: %   RETURN VALUE:
tomwalters@0: %       sigresult:  smoothed @signal
tomwalters@0: %
tomwalters@0: % smoothes the signal by multipliing it with gaussian filters of
tomwalters@0: % the width "sigma" in ms
tomwalters@0: %
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: function sig=smooth(org_sig,sigma, type)
tomwalters@0: 
tomwalters@0: % vals=getvalues(org_sig);
tomwalters@0: % % check sigma 
tomwalters@0: % if sigma<3
tomwalters@0: %     sigma==3
tomwalters@0: % end
tomwalters@0: % if mod(sigma, 2)==0
tomwalters@0: %     sigma=sigma+1
tomwalters@0: % end
tomwalters@0: % % Generate Kernel
tomwalters@0: % t = (-2*sigma):(2*sigma);
tomwalters@0: % kernel = 1/(sqrt(2*pi)*sigma)*exp(-(t).^2/(2*sigma.^2));
tomwalters@0: % 
tomwalters@0: if (nargin<3)
tomwalters@0:     type='gauss';
tomwalters@0: end
tomwalters@0: 
tomwalters@0: vals=getvalues(org_sig);
tomwalters@0: new_vals=vals; 
tomwalters@0: % Stefans's version
tomwalters@0: if strcmp(type,'gauss')
tomwalters@0:     nr_points=getnrpoints(org_sig);
tomwalters@0:     smooth_base=1:nr_points;
tomwalters@0:     smooth_frame = zeros(nr_points,1);
tomwalters@0:     for ii = 1:nr_points
tomwalters@0: %         kernel = exp(-(smooth_base-ii).^2/(2*sigma^2));
tomwalters@0:         kernel = exp(-(((smooth_base-ii).*(smooth_base-ii))/(2*sigma*sigma)));
tomwalters@0:         kernel = kernel / sum(kernel);
tomwalters@0:         new_vals(ii) = sum(vals.*kernel');
tomwalters@0:     end
tomwalters@0: end
tomwalters@0: if strcmp(type, 'rect')
tomwalters@0:    nr_points=getnrpoints(org_sig); 
tomwalters@0:    % mirroring the border
tomwalters@0:    sigma=round(sigma);
tomwalters@0:    vals=vals';
tomwalters@0:    if (length(vals)<sigma)
tomwalters@0:        sig=signal(org_sig);
tomwalters@0:        results(1:nr_points) = mean(vals');
tomwalters@0:        sig=setvalues(sig, results');
tomwalters@0:        return;
tomwalters@0:    end
tomwalters@0:    vals = [upsidedown(vals(1:sigma)) vals upsidedown(vals((end-sigma+1):end))];
tomwalters@0: %    kernel = ones(1, (2*sigma+1));
tomwalters@0: %    kernel = kernel/sum(kernel);
tomwalters@0:    faktor = 1/(2*(sigma+1));
tomwalters@0:    vals = vals.*faktor;
tomwalters@0:    for i=1:nr_points
tomwalters@0:        new_vals(i) = sum(vals(i:(i+2*sigma)));
tomwalters@0:    end
tomwalters@0:    new_vals=new_vals';
tomwalters@0: end
tomwalters@0: 
tomwalters@0: 
tomwalters@0:  
tomwalters@0: sig=signal(org_sig);
tomwalters@0: sig=setvalues(sig, new_vals);
tomwalters@0: sig=setname(sig, sprintf('smoothed Signal %s', getname(org_sig)));
tomwalters@0: 
tomwalters@0: 
tomwalters@0: 
tomwalters@0: % turns a vector (row) upside down
tomwalters@0: function y=upsidedown(x)
tomwalters@0: y=[];
tomwalters@0: for i=length(x):-1:1
tomwalters@0:     y=[y x(i)];
tomwalters@0: end