38 lines
1.3 KiB
C#
38 lines
1.3 KiB
C#
// Taken from https://github.com/Kaynn-Cahya/Shannon-Entropy with no license given.
|
|
// Since this was published on nuget, i am assuming the author is ok with it being used in open source
|
|
using System;
|
|
using System.Collections.Generic;
|
|
using System.Linq;
|
|
|
|
// Test: testEntropy.cs
|
|
namespace ShannonEntropyCal
|
|
{
|
|
public class EntropyCal
|
|
{
|
|
|
|
public static double EntropyValue(string message)
|
|
{
|
|
Dictionary<char, int> K = message.GroupBy(c => c).ToDictionary(g => g.Key, g => g.Count());
|
|
double EntropyValue = 0;
|
|
foreach (var character in K)
|
|
{
|
|
double PR = character.Value / (double) message.Length;
|
|
EntropyValue -= PR * Math.Log(PR, 2);
|
|
}
|
|
return EntropyValue;
|
|
}
|
|
|
|
public static double EntropyBits(string message)
|
|
{
|
|
Dictionary<char, int> K = message.GroupBy(c => c).ToDictionary(g => g.Key, g => g.Count());
|
|
double EntropyValue = 0;
|
|
foreach (var character in K)
|
|
{
|
|
double PR = character.Value / (double) message.Length;
|
|
EntropyValue -= PR * Math.Log(PR, 2);
|
|
}
|
|
return Math.Ceiling(EntropyValue) * message.Length;
|
|
}
|
|
}
|
|
}
|