function pws2textgrid (X,fname)

% PWS2TEXTGRID : writes Phrase-Word-Syllable structure Praat-format TextGrid file
%
% pws2textgrid (X,fname)
% If X is a PWS structure then the file created is [X.filename '.TextGrid']
% If X is an array of PWS structs then the file created is [X{i}.filename '.TextGrid'] for each i.
%
% Dinoj Surendran dinoj@cs.uchicago.edu 28 Dec 2005
%
% Assumptions: there could be pauses between words of the same phrase, 
%              but not between syllables of the same word.
% Notes
% (1) On the Word and Syllable Tiers, any segment of non-speech is labeled with SIL.
% (2) On the Phrase Tier, phrases are labeled by phrase number (a positive integer), 
%      and separated by -1.
% (3) A word can be valid or invalid.
%
% See http://people.cs.uchicago.edu/~dinoj/tonerec/ for more details

if (nargin<2)
  fname = X.filename;         
end
fid = fopen([fname '.TextGrid'],'wt');

if isfield(X,'filename')
  fprintf(fid,'File type = \"ooTextFile\"\n');
  fprintf(fid,'Object class = \"TextGrid\"\n\n');
  fprintf(fid,'xmin = %f\n',X.phrases{1}.startwords(1));
  fprintf(fid,'xmax = %f\n', X.phrases{end}.endwords(end));
  fprintf(fid,'tiers? <exists>\n');
  fprintf(fid,'size = 4\n');          % tiers for phrase / word / syllable / phonemes
  fprintf(fid,'item []:\n');
  
  % print Phrase TextTier
  
  fprintf(fid,'  item [1]:\n');
  fprintf(fid,'    class = \"IntervalTier\"\n');
  fprintf(fid,'    name = \"phrase\"\n');
  fprintf(fid,'    xmin = %f\n', X.phrases{1}.startwords(1) );
  fprintf(fid,'    xmax = %f\n', X.phrases{end}.endwords(end)  );
  fprintf(fid,'    intervals: size = %d\n',-1+2*length(X.phrases ));
  
  for j=1:length(X.phrases)
    fprintf(fid, '    intervals[%d] :\n',2*j-1);    % interval indices start at 1
    fprintf(fid, '      xmin = %f\n',X.phrases{j}.startwords(1) );
    fprintf(fid, '      xmax = %f\n',X.phrases{j}.endwords(end) );
    fprintf(fid, '      text = \"%d\"\n',j);

    if (j<length(X.phrases))
      fprintf(fid, '    intervals[%d] :\n',2*j);
      fprintf(fid, '      xmin = %f\n',X.phrases{j}.endwords(end) );
      fprintf(fid, '      xmax = %f\n',X.phrases{j+1}.startwords(1) );
      fprintf(fid, '      text = \"-1\"\n');
    end
  end
  
  %%%%%%%% now print word TextTier %%%%%%%%%%%%
  
  fprintf(fid,'  item [2]:\n');
  fprintf(fid,'    class = \"IntervalTier\"\n');
  fprintf(fid,'    name = \"word\"\n');
  fprintf(fid,'    xmin = %f\n', X.phrases{1}.startwords(1) );
  fprintf(fid,'    xmax = %f\n', X.phrases{end}.endwords(end)  );

  count = 0;          % find out how many 'words' (including SIL) there are
  for j=1:length(X.phrases)
    for k=1:length(X.phrases{j}.words)
      count = count+1;
      if (k<length(X.phrases{j}.words))  % check for silence between words
	if (X.phrases{j}.startwords(k+1) > X.phrases{j}.endwords(k))
	  count = count+1;
	end
      elseif (j < length(X.phrases))  % this is the last word in the not-last phrase
	if (X.phrases{j+1}.startwords(1) > X.phrases{j}.endwords(end))
	  count = count + 1;
	end
      end      
    end
  end
  fprintf(fid,'    intervals: size = %d\n',count);
  
  count = 1;
  for j=1:length(X.phrases)
    for k=1:length(X.phrases{j}.words)

      fprintf(fid, '    intervals[%d] :\n',count);
      fprintf(fid, '      xmin = %f\n',X.phrases{j}.startwords(k) );
      fprintf(fid, '      xmax = %f\n',X.phrases{j}.endwords(k) );

      if ~(X.phrases{j}.validword(k))
        fprintf(fid, '      text = \"0\"\n');
	count = count+1;
      else
        fprintf(fid, '      text = \"%s\"\n',X.phrases{j}.words{k}.name);
	count = count+1;
      end
      if (k<length(X.phrases{j}.words))  % if this is not the last word in the phrase
                                           % check for silence between words
	  if (X.phrases{j}.startwords(k+1) > X.phrases{j}.endwords(k))
             fprintf(fid, '    intervals[%d] :\n',count);
	     fprintf(fid, '      xmin = %f\n',X.phrases{j}.endwords(k) );
   	     fprintf(fid, '      xmax = %f\n',X.phrases{j}.startwords(k+1));
 	     fprintf(fid, '      text = \"SIL\"\n');
	     count = count+1;
	  end
      elseif (j < length(X.phrases))  % this is the last word in the not-last phrase
          if (X.phrases{j+1}.startwords(1) > X.phrases{j}.endwords(end))
	    fprintf(fid, '    intervals[%d] :\n',count);
	    fprintf(fid, '      xmin = %f\n',X.phrases{j}.endwords(end) );
	    fprintf(fid, '      xmax = %f\n',X.phrases{j+1}.startwords(1));
	    fprintf(fid, '      text = \"SIL\"\n');
  	    count = count + 1;
	  end
      end

    end
  end
  
  
  %%%%%%%% now print syllable TextTier %%%%%%%%%%%%
  
  fprintf(fid,'  item [3]:\n');
  fprintf(fid,'    class = \"IntervalTier\"\n');
  fprintf(fid,'    name = \"syllable\"\n');
  fprintf(fid,'    xmin = %f\n', X.phrases{1}.startwords(1) );
  fprintf(fid,'    xmax = %f\n', X.phrases{end}.endwords(end)  );

  count = 0;          % find out how many 'syllables' (including SIL) there are
  for j=1:length(X.phrases)
    for k=1:length(X.phrases{j}.words)
       
      if ~(X.phrases{j}.validword(k))
        count = count + 1;
      else
        count = count+length(X.phrases{j}.words{k}.sylls);
      end
      % check for silence between syllables
      if  (X.phrases{j}.validword(k))
       for s=1:length(X.phrases{j}.words{k}.sylls)-1
	if (X.phrases{j}.words{k}.startsylls(s+1) > X.phrases{j}.words{k}.endsylls(s))
	  count = count + 1;
	end
       end
      end
      
      if (k<length(X.phrases{j}.words))  % check for silence between words
 	if (X.phrases{j}.startwords(k+1) > X.phrases{j}.endwords(k))
           count = count+1;
  	end
      elseif (j < length(X.phrases))         % check for silence between phrases
	if (X.phrases{j+1}.startwords(1) > X.phrases{j}.endwords(end))
	  count = count + 1;
	end
      end
    end
  end
  fprintf(fid,'    intervals: size = %d\n',count);
  
  count = 1;
  for j=1:length(X.phrases)
    for k=1:length(X.phrases{j}.words)
     if (~X.phrases{j}.validword(k)) % invalid words have one syllable (= "0")
	fprintf(fid, '    intervals[%d] :\n',count);
	fprintf(fid, '      xmin = %f\n',X.phrases{j}.startwords(k));
	fprintf(fid, '      xmax = %f\n',X.phrases{j}.endwords(k));
	fprintf(fid, '      text = \"0\"\n');
	count = count+1;
     else
       for s=1:length(X.phrases{j}.words{k}.sylls)
	st = X.phrases{j}.words{k}.startsylls(s);
	en = X.phrases{j}.words{k}.endsylls(s);
	fprintf(fid, '    intervals[%d] :\n',count);
	fprintf(fid, '      xmin = %f\n',st);
	fprintf(fid, '      xmax = %f\n',en);
	fprintf(fid, '      text = \"%s\"\n',X.phrases{j}.words{k}.sylls{s} );
	count = count+1;
	
	if s>1         % check for silence between syllables within a word
	  enprev = X.phrases{j}.words{k}.endsylls(s-1);
	  if (st > enprev) % as opposed to just =
	    fprintf(fid, '    intervals[%d] :\n',count);
	    fprintf(fid, '      xmin = %f\n',enprev);
	    fprintf(fid, '      xmax = %f\n',st);
	    fprintf(fid, '      text = \"SIL\"\n');
	    count = count+1;
	  elseif (st < enprev)
	    [k j s]
	    [enprev st en]
	    X.phrases{j}.words{k}.sylls{s}
	  end
	end
	
      end
     end
      
     if (k<length(X.phrases{j}.words))  % check for silence between words
	if (X.phrases{j}.startwords(k+1) > X.phrases{j}.endwords(k))
	  fprintf(fid, '    intervals[%d] :\n',count);
	  fprintf(fid, '      xmin = %f\n',X.phrases{j}.endwords(k) );
	  fprintf(fid, '      xmax = %f\n',X.phrases{j}.startwords(k+1));
	  fprintf(fid, '      text = \"SIL\"\n');
	  count = count+1;
	end
     else         % check for silence between phrases
	if (j < length(X.phrases))
	  if (X.phrases{j+1}.startwords(1) > X.phrases{j}.endwords(end))
	    fprintf(fid, '    intervals[%d] :\n',count);
	    fprintf(fid, '      xmin = %f\n',X.phrases{j}.endwords(end) );
	    fprintf(fid, '      xmax = %f\n',X.phrases{j+1}.startwords(1));
	    fprintf(fid, '      text = \"SIL\"\n');
	    count = count + 1;
	  end
	end
     end
    end
  end
  
  %%%%%%%% now print phoneme TextTier %%%%%%%%%%%%
  
  fprintf(fid,'  item [4]:\n');
  fprintf(fid,'    class = \"IntervalTier\"\n');
  fprintf(fid,'    name = \"phoneme\"\n');
  fprintf(fid,'    xmin = %f\n', X.phrases{1}.startwords(1) );
  fprintf(fid,'    xmax = %f\n', X.phrases{end}.endwords(end)  );

  count = 0;          % find out how many 'phonemes' (including SIL) there are
  for j=1:length(X.phrases)
    for k=1:length(X.phrases{j}.words)
      if (~X.phrases{j}.validword(k))
        count = count + 1;  % invalid words have just one phoneme (= "0") plus the silence
      else
        count = count + length(X.phrases{j}.words{k}.phones);
      end
      if (k<length(X.phrases{j}.words))  % check for silence between words
	  if (X.phrases{j}.startwords(k+1) > X.phrases{j}.endwords(k))
	    count = count+1;
	  end
      elseif (j < length(X.phrases))
	  if (X.phrases{j+1}.startwords(1) > X.phrases{j}.endwords(end))
	     count = count + 1;
	  end
      end
    end
  end

  fprintf(fid,'    intervals: size = %d\n',count);
  
  count = 1;
  for j=1:length(X.phrases)
    for k=1:length(X.phrases{j}.words)
      if (~X.phrases{j}.validword(k))
	fprintf(fid, '    intervals[%d] :\n',count);
	fprintf(fid, '      xmin = %f\n',X.phrases{j}.startwords(k));
        fprintf(fid, '      xmax = %f\n',X.phrases{j}.endwords(k));
	fprintf(fid, '      text = \"0\"\n');
	count = count+1;
      else
        for s=1:length(X.phrases{j}.words{k}.phones)
	  fprintf(fid, '    intervals[%d] :\n',count);
     	  fprintf(fid, '      xmin = %f\n',X.phrases{j}.words{k}.startphones(s) );
	  fprintf(fid, '      xmax = %f\n',X.phrases{j}.words{k}.endphones(s) );
	  fprintf(fid, '      text = \"%s\"\n',X.phrases{j}.words{k}.phones{s} );
	  count = count+1;
        end
        % no checking for silence between phonemes of each word
      end

      if (k<length(X.phrases{j}.words))  % check for silence between words
	if (X.phrases{j}.startwords(k+1) > X.phrases{j}.endwords(k))
	  fprintf(fid, '    intervals[%d] :\n',count);
	  fprintf(fid, '      xmin = %f\n',X.phrases{j}.endwords(k) );
	  fprintf(fid, '      xmax = %f\n',X.phrases{j}.startwords(k+1));
	  fprintf(fid, '      text = \"SIL\"\n');
	  count = count+1;
	end
      elseif ((j < length(X.phrases)) && (X.phrases{j+1}.startwords(1) > X.phrases{j}.endwords(end)))
         % and k==length(X.phrases{j}.words)
	  fprintf(fid, '    intervals[%d] :\n',count);
	  fprintf(fid, '      xmin = %f\n',X.phrases{j}.endwords(end) );
	  fprintf(fid, '      xmax = %f\n',X.phrases{j+1}.startwords(1));
	  fprintf(fid, '      text = \"SIL\"\n');
	  count = count + 1;
      end      
    end
  end
end	    


fclose(fid);