For a real number xx, its ceiling x\lceil x\rceil is the unique integer satisfying

x1<xx.\lceil x\rceil-1<x\le\lceil x\rceil.

Equivalently, x=x\lceil x\rceil=-\lfloor-x\rfloor, where the brackets on the right denote the .

Scale comparison

For x1x\ge1,

xx<x+12x.x\le\lceil x\rceil<x+1\le2x.

Thus replacing a positive real frequency scale by its ceiling gives an integer scale with comparable size. For example, 2.3=3\lceil2.3\rceil=3 and 2.3=2\lceil-2.3\rceil=-2.