Plotyy with bars stacked

I am trying to do a matlab plot with two y axes. I want both to plots to be of type 'bars'. I can't work out how to make them stacked an how to hace axes going from 1:3 with out overlapping each other.

Here's what I do.

y = {rand(x, 1) * 100; (-0:(0.8)/(x-1):0.8)'};
fn1=@(x,y) bar(x , y, 0.3, 'FaceColor','r');
fn2=@(x,y) bar(x , y, 0.3, 'FaceColor','b');

[ax, hbar1, hbar2]=plotyy(1:2:6, y{1},2:2:6,y{2} ,fn1,fn2);