graph log2

https://drive.google.com/file/d/0B_6oLxv-7mehU2tLSkRkaGxtX1k/view?usp=sharing
1. n=[3 5 9 17 33 65];
2. s=[2.57e-1 6.46e-2 1.51e-2 3.96e-3 9.78e-4 2.45e-4];
3. plot2d(n,s,style=-1,logflag='ll')
4. plot2d(n,s,style=1,logflag='ll')