public void Next()
{
var mean = 2.0;
var count = 100000;
var values = Enumerable.Range(0, count)
.Select(i => ExponentialDistribution.Next(mean))
.OrderBy(x => x)
.ToArray();
Console.WriteLine($"Mean of Values: {values.Average()}");
var largeValues = values.SkipWhile(x => x < mean).ToArray();
// 1/e
Console.WriteLine($"Large Count Ratio: {(double)largeValues.Length / count}");
// 2/e
Console.WriteLine($"Large Sum Ratio: {largeValues.Sum() / (mean * count)}");
Console.WriteLine();
foreach (var g in values.GroupBy(x => (int)x))
{
Console.WriteLine($"{g.Key}: {g.Count()}");
}
Console.WriteLine();
foreach (var g in values.GroupBy(x => Math.Floor(x * 10) / 10))
{
Console.WriteLine($"{g.Key:F1}: {g.Count()}");
}
}
public static void Main(string[] args)
{
int N = 100; // Number of customers
double h = 0.20; // Percentage ex: 20% of all customers use 80% of the resources(VMs)
int totalVMs = 50000; // Total number of VMs
double[] weightPercentageArray; // Array to store the percentage of allocation of the resources.
// Create a Self-Similar Distribution
SelfSimilarDistribution selfsimilar = new SelfSimilarDistribution(N, h);
// Function returns how much weight to allocate resources to a given virtual user
selfsimilar.Samples(out weightPercentageArray);
Console.WriteLine("Self-Similar Distribution");
Console.WriteLine("AllocatedVMs %Allocation Iteration: ");
for (int i = 0; i < N; i++)
{
long allocatedVMs = (long)Math.Round((weightPercentageArray[i] * totalVMs));
Console.WriteLine("{0},{1:N3},{2}", allocatedVMs, weightPercentageArray[i] * 100, i);
}
Console.WriteLine("Press any key to continue...");
Console.ReadKey(true);
// Create an exponential distribution
double rate = 5; // On average get 5 events per unit of time (ex: 5 per min).
ExponentialDistribution exponentialDistribution = new ExponentialDistribution(rate);
Console.WriteLine("Exponential Distribution");
double[] exponentialArray; // Array to store the exponential random numbers
exponentialDistribution.Samples(out exponentialArray, N);
for (int i = 0; i < N; i++)
{
Console.WriteLine("{0:N9},{1}", exponentialArray[i] * 60, i); // Multiply by 60 to convert in seconds
}
Console.WriteLine("Press any key to continue...");
Console.ReadKey(true);
// Another example on how to use the exponentialDistribution function
// Fire an event at rate of 5 events per minutes
ConsoleKeyInfo cki;
Console.WriteLine("Fire an event at rate of 5 events per minutes");
do
{
int exponentialRandom = (int)(exponentialDistribution.Next() * 60000); // Multiply by 60000 to convert in milliseconds
Console.WriteLine("Waiting {0} milliseconds before firing the next event", exponentialRandom);
// Wait for thread
System.Threading.Thread.Sleep(exponentialRandom);
Console.WriteLine("Firing event.");
Console.WriteLine("Press ESC to stop.");
cki = Console.ReadKey(true);
} while (cki.Key != ConsoleKey.Escape);
}
