Added frequency analysis

FastRngTests/Double/FrequencyAnalysis.cs

@@ -0,0 +1,83 @@
+using System;
+using System.Linq;
+using System.Runtime.CompilerServices;
+using System.Text;
+
+namespace FastRngTests.Double
+{
+    public sealed class FrequencyAnalysis
+    {
+        private readonly uint[] data;
+        
+        public FrequencyAnalysis(int samples = 100)
+        {
+            this.data = new uint[samples];
+        }
+
+        public void CountThis(double value)
+        {
+            var bucket = (int)Math.Floor(value * this.data.Length);
+            this.data[bucket]++;
+        }
+
+        public double[] GetNormalizedEvents()
+        {
+            var max = (double) this.data.Max();
+            var result = new double[this.data.Length];
+            for (var n = 0; n < this.data.Length; n++)
+            {
+                result[n] = this.data[n] / max;
+            }
+
+            return result;
+        }
+
+        private double[] Normalize()
+        {
+            var max = (double)this.data.Max();
+            var result = new double[this.data.Length];
+            for (var n = 0; n < this.data.Length; n++)
+                result[n] = this.data[n] / max;
+
+            return result;
+        }
+
+        public double[] NormalizeAndPlotEvents(Action<string> writer)
+        {
+            var result = this.Normalize();
+            FrequencyAnalysis.Plot(result, writer, "Event Distribution");
+            
+            return result;
+        }
+        
+        public void PlotOccurence(Action<string> writer)
+        {
+            var data = this.data.Select(n => n > 0 ? 1.0 : 0.0).ToArray();
+            FrequencyAnalysis.Plot(data, writer, "Occurrence Distribution");
+        }
+
+        private static void Plot(double[] data, Action<string> writer, string name)
+        {
+            const int HEIGHT = 16;
+            
+            var values = new double[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);
+        }
+    }
+}