function w = taper(w,R, style)
   
   % WAVEFORM = TAPER(WAVEFORM,R) applies a cosine taper to the ends of a
   % trace where r is the ratio of tapered to constant sections and is between
   % 0 and 1. For example, if R = 0.1 then the taper at each end of the trace
   % is 5% of the total trace length. R can be either a scalar or the same
   % size as WAVEFORM. If R is a scalar, it is applied uniformly to each
   % waveform. Note that if R is set to 1 the resulting taper is a hanning
   % window.
   %
   % WAVEFORM = TAPER(WAVEFORM) same as above with a default taper of R = 0.2.
   %
   % TODO: Currently, only cosine tapers are supported. The code is set up to
   % accept other window shapes as a final argument, e.g.
   % taper(waveform,R,'cosine'). However other window shapes have not yet been
   % implimented. - MEW
   
   % AUTHOR: Michael West
   % $Date$
   % $Revision$
   % Modified: Celso Reyes
   
   
   % CHECK WAVEFORM
   if ~strcmpi(class(w),'waveform')
      error('Waveform:taper:missingWaveform',...
         'First input must be a waveform object');
   end
   
   if ~exist('R','var') || isempty(R)
      R = 0.2; %assign default taper
   elseif ~isnumeric(R)
      error('Waveform:taper:InvalidRValue',...
         'R, if specified, must be numeric');
   end
   
   if ~exist('style','var') || isempty(style)
      style = 'COSINE';
   end
   
   
   if isscalar(R)
      R = repmat(R,size(w));
   end
   
   if (isvector(R) && isvector(w)) && numel(R) == numel(w)
      if all(size(w)) ~= size(R)
         % same number of elements, but R is Nx1 and w is 1xN or vice-versa
         warning('Waveform:taper:columnsVsRows',...
            ['One input (either R or the wavform) is arranged in '...
            'columns while the other is arranged in Rows.  While they '...
            'should be the same shape, taper is continuing with R''']);
         R = R';
      end
   end
   
   if ~all(size(w) == size(R))
      error('Waveform:taper:InvalidRSize',...
         'R must either be a scalar value, or must be the same size as the input waveforms');
   end
   
   switch upper(style)
      case 'COSINE'
         for n=1:numel(w)
            w(n) = docosine(w(n),R(n));
         end
      case 'GAUSSIAN'
         %not implemented, placeholder only.
         error('Waveform:taper:invalidTaperType',...
            'Gaussian taper is not yet implimented');
      otherwise
         error('Waveform:taper:invalidTaperType',...
            'This style of taper is not recognized.');
   end;
end
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% apply cosine taper to waveforms
function w = docosine(w,r)
   %applied to individual waveforms only
   w = w .* tukeywin( numel(w.data) , r );
end



