function y=ternary(x,n)
%Returns the first n digits of the ternary expansion of x,
%where it is assumed that 0<=x<=1

currentbase=3;
for j=1:n
   if x< (1/currentbase)
      y(j)=0
   elseif x<(2/currentbase)
      y(j)=1
   else
      y(j)=2
   end
   x=x-(y(j)/currentbase);
   currentbase=currentbase*3;
end