net.imagej.ops.filter.fftSize

## Class NextSmoothNumber

• ```public class NextSmoothNumber
extends Object```
A class to determine the next k-smooth number (i.e. a number divisible only by prime numbers up to k), given a lower bound n. Based on A. Granville, Smooth numbers: computational number theory and beyond:
5.7. Finding smooth numbers computationally. The obvious way to find y-smooth numbers in (x; x + z) with z ≤ x is to initialize an array a[i] := 0 for 1 ≤ i ≤ z (where a[i] corresponds to x + i). For each successively larger prime power pj ≤ x + z with p ≤ y, determine the smallest i such that pj divides x + i and then add log(p) to a[i], a[i + pj], a[i + 2pj] and so on, up until the end of the array. When we’ve finished, if any a[i] ≥ log(x), then x + i is y-smooth.
Author:
Johannes Schindelin, Brian Northan
• ### Constructor Summary

Constructors
Constructor and Description
`NextSmoothNumber()`
• ### Method Summary

All Methods
Modifier and Type Method and Description
`static void` `main(String... args)`
`static int` `nextSmooth(int x)`
`static int` ```nextSmooth(int y, int x, int z)```
• ### Methods inherited from class java.lang.Object

`clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`
• ### Constructor Detail

• #### NextSmoothNumber

`public NextSmoothNumber()`
• ### Method Detail

• #### nextSmooth

`public static int nextSmooth(int x)`
• #### nextSmooth

```public static int nextSmooth(int y,
int x,
int z)```
• #### main

`public static void main(String... args)`