function  giffoil(filename)
% This is a simple matlab plotting function for use with the 
% airfoil data files obtained from the
% University of Illinois at Urbana-Champaign
%
% usage:
%  pf('filename')    
%  note .dat extension is assumed
%
   datafile = [filename '.dat'];
   giffile  = ['gifs/' filename '.gif'];

   fid = fopen(datafile,'r');
   if (fid == -1)
      fprintf(1,'error opening %s\n',datafile);
      return;
   end

   name         = fgetl(fid);
   [pts,count]  = fscanf(fid,'%f');

   fclose(fid);

   if ( (pts(1) == floor(pts(1))) & (pts(1)>5) )
        % "Lednicers" format
        npts_top = pts(1);
        npts_bot = pts(2);

        top = zeros(2,npts_top);
        bot = zeros(2,npts_bot);
        
        tp = pts(3:2+2*npts_top);
        bt = pts(3+2*npts_top:2+2*npts_top+2*npts_bot);
        
        top(:) = tp;
        bot(:) = bt;

        h=figure('visible','off');

        plot(top(1,:),top(2,:),'w');
        hold on
        plot(bot(1,:),bot(2,:),'w');
        axis([0 1 -.5 .5]);
        title(name);
   elseif (length(pts)/2 == floor(length(pts)/2))
        % "selig"  format assumed...
        npts = length(pts)/2;
        foil = zeros(2,npts);
        foil(:) = pts;
        h=figure('visible','off');

        plot(foil(1,:),foil(2,:),'w');
        axis([0 1 -.5 .5]);
        title(name);
   else    % n x y format assumed
        npts = length(pts)/3;
        if (npts ~= floor(npts))
           fprintf(1,'error interpreting %s\n',datafile);
           return;
        end 
        foil = zeros(3,npts);
        foil(:) = pts;
        h=figure('visible','off');

        plot(foil(2,:),foil(3,:),'w');
        axis([0 1 -.5 .5]);
        title(name);
   end
   status = 0;

   axis([0 1 -0.5 0.5]);
   set(gcf,'paperposition',[0 0 7.2 6.8]);
   print -dps figure.ps
   close;

   gsfname = 'gs.cmd';
   gsfid = fopen (gsfname, 'w');
 
   fprintf(gsfid,'-dNOPAUSE -q\n');
   fprintf(gsfid,'-I/packages/matlab/ghostscript/ps_files\n');
   fprintf(gsfid,'-I/packages/matlab/ghostscript/fonts\n');
   fprintf(gsfid,'-sDEVICE=gif8\n');
   fprintf(gsfid,'-g500x500\n');
   fprintf(gsfid,'-sOutputFile=%s\n',giffile);
   fclose(gsfid);

   status=unix('/packages/matlab/ghostscript/bin/sun4/gs @gs.cmd figure.ps </dev/null >/dev/null');

   if (status ~=0)
      fprintf(1,'unix status %i\n', status);
   else
      fprintf(1,'%s converted ok\n',datafile);
   end

return