/// <summary>
/// Gets the next precision of Pi value based on the previous value. If there were no previous value, a new Pi value is created from scratch.
/// Follows the Liebniz formula for pi. ref http://en.wikipedia.org/wiki/Leibniz_formula_for_%CF%80
/// </summary>
/// <param name="previousEstimate">previous estimate</param>
/// <returns>new estimate value</returns>
public static Estimate PI(Estimate previousEstimate)
{
if (previousEstimate == null)
{
return(new Estimate());
}
int prevCount = previousEstimate.IterationCount;
int fraction = (previousEstimate.IterationCount * 2) + 1;
int count = prevCount + 1;
double denominator = fraction;
double newValue;
if (count % 2 != 0)
{
newValue = previousEstimate.EstimatedValue + (LeibnizNumerator / denominator);
}
else
{
newValue = previousEstimate.EstimatedValue - (LeibnizNumerator / denominator);
}
Estimate e = new Estimate();
e.IterationCount = count;
e.EstimatedValue = newValue;
return(e);
}
/// <summary>
/// Gets the next precision of Pi value based on the previous value. If there were no previous value, a new Pi value is created from scratch.
/// Follows the Liebniz formula for pi. ref http://en.wikipedia.org/wiki/Leibniz_formula_for_%CF%80
/// </summary>
/// <param name="previousEstimate">previous estimate</param>
/// <returns>new estimate value</returns>
public static Estimate PI(Estimate previousEstimate)
{
if (previousEstimate == null)
{
return new Estimate();
}
int prevCount = previousEstimate.IterationCount;
int fraction = (previousEstimate.IterationCount*2) + 1;
int count = prevCount + 1;
double denominator = fraction;
double newValue;
if (count%2 != 0)
{
newValue = previousEstimate.EstimatedValue + (LeibnizNumerator/denominator);
}
else
{
newValue = previousEstimate.EstimatedValue - (LeibnizNumerator/denominator);
}
Estimate e = new Estimate();
e.IterationCount = count;
e.EstimatedValue = newValue;
return e;
}
/// <summary>
/// Compares two <see cref="Estimate"/> values
/// </summary>
/// <param name="x">First estimate</param>
/// <param name="y">Second estimate</param>
/// <returns>true if <paramref name="x"/> is exactly equal to <paramref name="y"/></returns>
public static bool Equals(Estimate x, Estimate y)
{
if (x == y)
{
return(true);
}
if (x == null || y == null)
{
return(true);
}
return(x.IterationCount == y.IterationCount && x.EstimatedValue == y.EstimatedValue);
}
/// <summary>
/// Compares two <see cref="Estimate"/> values
/// </summary>
/// <param name="x">First estimate</param>
/// <param name="y">Second estimate</param>
/// <returns>true if <paramref name="x"/> is exactly equal to <paramref name="y"/></returns>
public static bool Equals(Estimate x, Estimate y)
{
if (x == y)
{
return true;
}
if (x == null || y == null)
{
return true;
}
return x.IterationCount == y.IterationCount && x.EstimatedValue == y.EstimatedValue;
}
protected override async Task RunAsync(CancellationToken cancellationToken)
{
Trace.WriteLine("Starting Pi estimation.");
try
{
IReliableDictionary <int, Estimate> estimateDictionary =
await this.StateManager.GetOrAddAsync <IReliableDictionary <int, Estimate> >("estimateDictionary");
while (true)
{
cancellationToken.ThrowIfCancellationRequested();
using (ITransaction tx = this.StateManager.CreateTransaction())
{
await estimateDictionary.AddOrUpdateAsync(
tx,
1,
Estimate.PI(null),
(key, value) =>
{
Estimate next = Estimate.PI(value);
ServiceEventSource.Current.ServiceMessage(this, next.ToString());
return(next);
});
await tx.CommitAsync();
}
await Task.Delay(TimeSpan.FromSeconds(1), cancellationToken);
}
}
catch (Exception ex)
{
Trace.WriteLine(ex);
throw;
}
}
/// <summary>
/// Compares this instance to another <see cref="Estimate"/>
/// </summary>
/// <param name="x">the <see cref="Estimate"/> to compare with</param>
/// <returns>true if this <see cref="Estimate"/> is exactly equal to <paramref name="x"/></returns>
public bool Equals(Estimate x)
{
return(Equals(this, x));
}
/// <summary>
/// Compares this instance to another <see cref="Estimate"/>
/// </summary>
/// <param name="x">the <see cref="Estimate"/> to compare with</param>
/// <returns>true if this <see cref="Estimate"/> is exactly equal to <paramref name="x"/></returns>
public bool Equals(Estimate x)
{
return Equals(this, x);
}
