function  []=write_ptr(a,ptr_out);
%  write_PTR write each line of EPIC pointer file from cell array a
%  USAGE: function  []=write_ptr(a,ptr_out);
%
%  Inputs:  
%      a = cell array containing one line of pointer file per cell
%      ptr_out = pointer file name (string)

fid=fopen(ptr_out,'wt');
for i=1:length(a);
  fprintf(fid,'%s\n',a{i});
end
fclose(fid);
