function printFormat6(x,y,z)

% -- File output:  optional use of tabs to separate columns
fprintf('\nWrite data to a file, no screen output:\n');
fout = fopen('someData.txt','wt');
fprintf(fout,'j\tx(j)\ty(j)\tz(j)\n');
for j=1:length(x)
  fprintf(fout,'%d\t%e\t%e\t%e\n',j,x(j),y(j),z(j));
end
fclose(fout);  % always close the open file handle