dtstem.m

trabajos en matlab para verificar son muy buenos

function dtstem(line_han,x,y,mode)
% DTSTEM Generates stem plots for various ADSP GUIs.


% ADSP Toolbox: Version 2.0 
% For use with "Analog and Digital Signal Processing", 2nd Ed.
% Published by PWS Publishing Co.
%
% Ashok Ambardar, EE Dept. MTU, Houghton, MI 49931, USA
% http://www.ee.mtu/faculty/akambard.html
% e-mail: [e-mail]
% Copyright (c) 1998


if nargin<4,mode=0;end
% if nothing to plot, clear old plot and get out
if ~length(y),
   return;
end

%ver_str = version;
ver4=0;  %ver4    = length(findstr('4.',ver_str));

% clean up line_han.  this is to remove any
% text objects that are being stored to keep track
% of the custom signal components
loc = [];
for k = 1:length(line_han),
   if ~strcmp(get(line_han(k),'type'),'line'),
      loc = [loc,k];
   end
end
if length(loc), line_han(loc) = []; end

ly = length(y);

% make line data a row vector
y_d = y(:)';
x_d = x(:)';

if ly > 127 & mode==0,
   if ver4,
      set(line_han(1),'xdata',x_d,'ydata',y_d,'linestyle','-');
      set(line_han(2),'xdata',x_d,'ydata',y_d,'linestyle','-');
   else
      set(line_han(1),'xdata',x_d,'ydata',y_d,'linestyle','-',...
                      'marker','none');
      set(line_han(2),'xdata',x_d,'ydata',y_d,'linestyle','-',...
                      'marker','none');
   end


else

% add the zero row vector
   y_d = [y_d;zeros(1,ly)];
   x_d = [x_d; x_d];

% add the NaN row vector
   y_d = [y_d;zeros(1,ly)+NaN];
   x_d = [x_d;zeros(1,ly)+NaN];

% reshape into a column vector
   y_d = y_d(:);
   x_d = x_d(:);

% update current plot
   if ver4,
      set(line_han(1),'xdata',x_d,'ydata',y_d,'linestyle','-');

      lin_data = get(line_han(2),'userdata');
      if length(lin_data),
         set(line_han(2),'xdata',x,'ydata',y,'linestyle',lin_data);
      else
         set(line_han(2),'xdata',x,'ydata',y,'linestyle','o','marker',4);
      end
   else
      set(line_han(1),'xdata',x_d,'ydata',y_d,'linestyle','-',...
                      'marker','none');

      lin_data = get(line_han(2),'userdata');
      if length(lin_data),
         set(line_han(2),'xdata',x,'ydata',y,'marker',lin_data,...
                         'linestyle','none');
      else
         set(line_han(2),'xdata',x,'ydata',y,'marker','o',...
                         'markersize',4,'linestyle','none');
      end
   end

end