FastRng/FastRngTests/FrequencyAnalysis.cs

using System;
using System.Diagnostics.CodeAnalysis;
using System.Linq;
using System.Text;

namespace FastRngTests;

[ExcludeFromCodeCoverage]
public sealed class FrequencyAnalysis
{
    private readonly uint[] data;
        
    public FrequencyAnalysis(int samples = 100)
    {
        this.data = new uint[samples];
    }

    public void CountThis(float value)
    {
        var bucket = (int)MathF.Floor(value * this.data.Length);
        this.data[bucket]++;
    }

    public float[] GetNormalizedEvents()
    {
        var max = (float) this.data.Max();
        var result = new float[this.data.Length];
        for (var n = 0; n < this.data.Length; n++)
        {
            result[n] = this.data[n] / max;
        }

        return result;
    }

    private float[] Normalize()
    {
        var max = (float)this.data.Max();
        var result = new float[this.data.Length];
        for (var n = 0; n < this.data.Length; n++)
            result[n] = this.data[n] / max;

        return result;
    }

    public float[] NormalizeAndPlotEvents(Action<string> writer)
    {
        var result = this.Normalize();
        Plot(result, writer, "Event Distribution");
            
        return result;
    }
        
    public void PlotOccurence(Action<string> writer)
    {
        var data = this.data.Select(n => n > 0f ? 1.0f : 0.0f).ToArray();
        Plot(data, writer, "Occurrence Distribution");
    }

    private static void Plot(float[] data, Action<string> writer, string name)
    {
        const int HEIGHT = 16;
            
        var values = new float[data.Length];
        for (var n = 0; n < data.Length; n++)
        {
            values[n] = data[n] * HEIGHT;
        }

        var sb = new StringBuilder();
        for (var line = HEIGHT; line > 0; line--)
        {
            for (var column = 0; column < data.Length; column++)
                sb.Append(values[column] >= line ? '█' : '░');
                
            writer.Invoke(sb.ToString());
            sb.Clear();
        }
            
        writer.Invoke(name);
        writer.Invoke(string.Empty);
    }
}