function disptrell(dlt,slt,data_est,state_est,varargin)%DISPTRELL Display decoding process in graphical form.%   DISPTRELL(DLT,SLT,D_E,S_E) displays most probable path and data%   estimations in decoding process. DLT and SLT look-up tables are%   required to display code trellis with all possible transitions. The%   DISPTRELL function doesn't affect the detection process. It's just a%   tool intended for lectures and presentations. As it belongs to the%   Visual Layer it's not included in the DETECT function to speed up%   decoding process.%%   DISPTRELL(...,'PropertyName',PropertyValue,...)%%   Disptrell Property List% %   Shrink         0 < SHRINK < {0.5}%%   See also DETECT.%   Copyright 2001-2003 Kamil Anis, anisk@feld.cvut.cz%   Dept. of Radioelectronics, %   Faculty of Electrical Engineering%   Czech Technical University in Prague%   $Revision: 2.1 $  $Date: 2003/1/16 17:33:28 $%   --%   <additional stuff goes here>name = 'DISPTRELL';[idt,tag] = iecho(name);[s,md,space_dim] = size(dlt);[symbols,foo,frames] = size(data_est);framecut = 15;% only one frame perfigure can be displayedif frames > 1  str5 = num2str(frames);  disp(' ');  disp([tag,'Data consists from ',str5,' frame(s).']);  disp([idt,'Only one frame per figure can be displayed!'])  disp(' ');  data_est = data_est(:,1,1);end% max 20 symbols can be displayedif symbols > 20  str6 = num2str(framecut);  disp(' ');  disp([tag,'Frame is too long!']);  disp([idt,'Only first ',str6,' symbols will be displayed.'])  disp(' ');	endstate = framecut;	data_est = data_est(1:framecut,1,1);else	endstate = symbols;end% default shrink factorif length(varargin) == 1	shrink = varargin{1};else	shrink = 1 / 2;	shrink_axis = (s + 1) * shrink;end%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% BODY BEGIN %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%offset = 0.1;clf;for k = 1:endstate	x1 = k; x2 = k + 1;	for i = 1:s		for j = 1:md			y1 = i;			y2 = slt(i,j,:);						trellis = line([x1 x2],[y1,y2]);			set(trellis,'LineStyle',':');		end		str = num2str(i);		text(0.5,i,str,'HorizontalAlignment','Center');	end	backpath = line([k k + 1],[state_est(k) state_est(k + 1)]);	set(backpath,'Color','red','LineWidth',2);	str1 = num2str(k);	text(k,s + 1,str1,'HorizontalAlignment','Center');		str2 = num2str(data_est(k));	str3 = text(k + offset,state_est(k) - offset,str2);	set(str3,'HorizontalAlignment','Center','FontWeight','bold');end%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% BODY END %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%text((endstate + 1) / 2,s + 2,'Steps [\itk\rm]')text(0.5,-0.5,'States','HorizontalAlignment','Center')legend([backpath;trellis],['Back path  ';'Transitions']);figtitle = ['Best path found with Viterbi iterative decoder'];wintitle = [name,': ',figtitle];ft = title(figtitle);set(ft,'FontWeight','bold','FontSize',12);set(gcf,'Name',wintitle);axis([1,endstate + 1,1 - (s / shrink_axis),s + (s / shrink_axis)]);axis off;view(0,-90);