Full cycle
From Wikipedia, the free encyclopedia
- For the record label, see Full Cycle Recordings
A full cycle is a mathematical term that represents a traversal over a set of non-random numbers. A full cycle implies that every number in the set was chosen exactly once before repeating.
Full cycles are useful in Pseudorandom number generators.
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[edit] Example 1 (in C++)
Given a random number seed that is greater or equal to zero. Given a total sample size greater than 1. Given a prime number that cannot be evenly divided into the total sample size.
A full cycle can be generated with the following logic. Each number in the sample_size should occur once.
unsigned int random_seed = 0;
unsigned int sample_size = 3000;
unsigned int generated_number = random_seed % sample_size;
unsigned int prime_number = 7;
unsigned int increment = prime_number;
for(unsigned int iterator = 0; iterator < sample_size; ++iterator)
{
generated_number = (generated_number + increment) % sample_size;
}
[edit] Example 2 (in C++)
// PseudoRandomTest1.cpp : Defines the entry point for the console application.
#include "stdafx.h"
void main(int argc, char* argv[])
{
unsigned int random_seed = 0;
const unsigned int sample_size = 3000;
unsigned int generated_number = random_seed % sample_size;
unsigned int prime_number = 1;
unsigned int increment = prime_number;
bool test[sample_size] = {0};
for(unsigned int iterator = 0; iterator < sample_size; ++iterator)
{
generated_number = (generated_number + increment) % sample_size;
test[generated_number] = true;
static bool displayOnce = true;
if (displayOnce)
{
printf("Predicable Random Numbers:\n");
displayOnce = false;
}
printf("%d ", generated_number);
}
for(unsigned int iterator = 0; iterator < sample_size; ++iterator)
{
if (!test[iterator])
{
static bool displayOnce = true;
if (displayOnce)
{
printf("\nYou must have not used a prime number [ERROR]\n");
displayOnce = false;
}
printf("%d ", iterator);
}
}
}
[edit] Example 2 (in C#)
using System;
using System.Collections.Generic;
using System.Text;
namespace PseudoRandomTest1
{
class Program
{
static Boolean m_DisplayOnce = false;
static void Main(string[] args)
{
const UInt32 random_seed = 0;
const UInt32 sample_size = 3000;
UInt32 generated_number = random_seed % sample_size;
const UInt32 prime_number = 751;
const UInt32 increment = prime_number;
Boolean[] test = new Boolean[sample_size];
m_DisplayOnce = true;
for(UInt32 iterator = 0; iterator < sample_size; ++iterator)
{
generated_number = (generated_number + increment) % sample_size;
test[generated_number] = true;
if (m_DisplayOnce)
{
Console.WriteLine("Predicable Random Numbers:");
m_DisplayOnce = false;
}
Console.Write("{0} ", generated_number);
}
m_DisplayOnce = true;
for(UInt32 iterator = 0; iterator < sample_size; ++iterator)
{
if (!test[iterator])
{
if (m_DisplayOnce)
{
Console.WriteLine();
Console.WriteLine("You must have not used a prime number [ERROR]");
m_DisplayOnce = false;
}
Console.Write("{0} ", iterator);
}
}
}
}
}
