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Arithmetic-geometric mean: Difference between revisions
Added implementation in C#.
(Added Common Lisp version) |
(Added implementation in C#.) |
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Line 104:
The AGM is : 0.847213
</pre>
=={{header|C sharp}}==
<lang csharp>namespace RosettaCode.ArithmeticGeometricMean
{
using System;
using System.Collections.Generic;
using System.Globalization;
internal static class Program
{
private static double ArithmeticGeometricMean(double number,
double otherNumber,
IEqualityComparer<double>
comparer)
{
return comparer.Equals(number, otherNumber)
? number
: ArithmeticGeometricMean(
ArithmeticMean(number, otherNumber),
GeometricMean(number, otherNumber), comparer);
}
private static double ArithmeticMean(double number, double otherNumber)
{
return 0.5 * (number + otherNumber);
}
private static double GeometricMean(double number, double otherNumber)
{
return Math.Sqrt(number * otherNumber);
}
private static void Main()
{
Console.WriteLine(
ArithmeticGeometricMean(1, 0.5 * Math.Sqrt(2),
new RelativeDifferenceComparer(1e-5)).
ToString(CultureInfo.InvariantCulture));
}
private class RelativeDifferenceComparer : IEqualityComparer<double>
{
private readonly double _maximumRelativeDifference;
internal RelativeDifferenceComparer(double maximumRelativeDifference)
{
_maximumRelativeDifference = maximumRelativeDifference;
}
public bool Equals(double number, double otherNumber)
{
return RelativeDifference(number, otherNumber) <=
_maximumRelativeDifference;
}
public int GetHashCode(double number)
{
return number.GetHashCode();
}
private static double RelativeDifference(double number,
double otherNumber)
{
return AbsoluteDifference(number, otherNumber) /
Norm(number, otherNumber);
}
private static double AbsoluteDifference(double number,
double otherNumber)
{
return Math.Abs(number - otherNumber);
}
private static double Norm(double number, double otherNumber)
{
return 0.5 * (Math.Abs(number) + Math.Abs(otherNumber));
}
}
}
}</lang>
Output:
<pre>0.847213084835193</pre>
=={{header|C++}}==
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