Added standard deviation

Examples/Common/Extensions/EnumerableExtensions.cs

@@ -4,13 +4,44 @@ public static class EnumerableExtensions
 {
   public static double Median(this IEnumerable<double> values)
   {
-    var tValues = values.ToArray();
-    return tValues
-      .OrderBy(x => x)
-      .Skip(tValues.Length / 2)
-      .First();
+    var tValues = values.OrderBy(v => v).ToArray();
+    if (!tValues.Any())
+    {
+      throw new ArgumentException(
+        "The list must contain at least one value for calculating the median");
+    }
+
+    if (tValues.Length % 2 != 0)
+    {
+      return tValues[tValues.Length / 2];
+    }
+
+    var center = tValues.Length / 2;
+    return (tValues[center - 1] + tValues[center]) / 2.0;
   }
 
-  public static double Median<T>(this IEnumerable<T> items, Func<T, double> selector) =>
-    items.Select(selector).Median();
+  public static double Median(this IEnumerable<double> values, out double deviation)
+  {
+    var tValues = values.ToArray();
+    var median = tValues.Median();
+    deviation = tValues.Select(value => Math.Abs(value - median)).Median();
+    return median;
+  }
+
+  public static double Average(this IEnumerable<double> values, out double deviation)
+  {
+    var tValues = values?.ToArray();
+    if (tValues is null || tValues.Length < 2)
+    {
+      throw new ArgumentException(
+        "The list must contain at least two values for calculating standard deviation");
+    }
+
+    var average = tValues.Average();
+
+    var diffSquaredSum = tValues.Sum(value => Math.Pow(value - average, 2));
+    deviation = Math.Sqrt(diffSquaredSum / (tValues.Length - 1));
+
+    return average;
+  }
 }

Examples/ReportGenerator/Generator/Generator/HtmlTableGenerator.cs

@@ -26,7 +26,7 @@ internal class CollapsibleHtmlTableGenerator : HtmlTableGenerator
   /// <inheritdoc />
   protected override void OnOpen()
   {
-    Writer.Write($"<details class={DetailsClass}>");
+    Writer.Write($"<details class=\"{DetailsClass}\" open>");
     Writer.Write(HtmlTools.Wrap("summary", Summary));
     base.OnOpen();
   }

Examples/ReportGenerator/Program.cs

@@ -23,9 +23,17 @@ internal static class Program
 
     using var document = new HtmlDocumentGenerator(path);
     using var report = new ReportGenerator("OCR Report", document, scans)
-      .AddComparison("Processing summary (Average)", v => v.Average())
+      .AddComparison("Processing summary (Average)", v =>
+      {
+        var result = v.Average(out var deviation);
+        return (result, deviation);
+      })
       // .AddComparison("Processing summary (Cumulative)", v => v.Sum())
-      .AddComparison("Processing summary (Median)", v => v.Median())
+      .AddComparison("Processing summary (Median)", v =>
+      {
+        var result = v.Median(out var deviation);
+        return (result, deviation);
+      })
       // .AddProcessorStats("Processor Stats")
       .AddImageStatsFull("Scan Results");
 

Examples/ReportGenerator/ReportGenerator.cs

@@ -143,7 +143,7 @@ public class ReportGenerator : IDisposable
 
   public ReportGenerator AddComparison(
     string title,
-    Func<IEnumerable<double>, double> evaluationFunc
+    Func<IEnumerable<double>, (double, double)> evaluationFunc
   )
   {
     var lookup = Images
@@ -153,28 +153,44 @@ public class ReportGenerator : IDisposable
     Document.AppendHeading(2, title);
 
     var byWer = lookup
-      .Select(g => (
-        Name: g.Key,
-        Value: evaluationFunc(g.Select(p => p.Distance)) * 100
-      ))
+      .Select(g =>
+      {
+        var (value, deviation) = evaluationFunc(g.Select(p => p.Distance * 100));
+        return (
+          Name: g.Key,
+          Value: value,
+          Deviation: deviation
+        );
+      })
       .OrderBy(g => g.Value);
     Document.AppendHeading(3, "WER");
     AppendComparison(("Error", "%"), byWer);
 
     var byCer = lookup
-      .Select(g => (
-        Name: g.Key,
-        Value: evaluationFunc(g.SelectMany(p => p.Words, (_, word) => word.Distance))
-      ))
+      .Select(g =>
+      {
+        var (value, deviation) =
+          evaluationFunc(g.SelectMany(p => p.Words, (_, word) => word.Distance));
+        return (
+          Name: g.Key,
+          Value: value,
+          Deviation: deviation
+        );
+      })
       .OrderBy(g => g.Value);
     Document.AppendHeading(3, "CER");
     AppendComparison(("Changes", string.Empty), byCer);
 
     var byTime = lookup
-      .Select(g => (
-        Name: g.Key,
-        Value: evaluationFunc(g.Select(p => p.ProcessingTime)) * 1000
-      ))
+      .Select(g =>
+      {
+        var (value, deviation) = evaluationFunc(g.Select(p => p.ProcessingTime * 1000));
+        return (
+          Name: g.Key,
+          Value: value,
+          Deviation: deviation
+        );
+      })
       .OrderBy(g => g.Value);
     Document.AppendHeading(3, "Time");
     AppendComparison(("Time", "ms"), byTime);
@@ -185,7 +201,7 @@ public class ReportGenerator : IDisposable
 
   private void AppendComparison(
     (string name, string unit)? valueInfo,
-    IEnumerable<(string, double)> values
+    IEnumerable<(string, double, double)> values
   )
   {
     const int context = 5;
@@ -193,10 +209,15 @@ public class ReportGenerator : IDisposable
     var tValues = values.ToArray();
     var tContext = Math.Min(tValues.Length / 2, context);
 
-    Document.AppendTable(2, table =>
+    Document.AppendTable(3, table =>
     {
       table
-        .AppendHeader(new[] { "Processor", valueInfo?.name ?? "Value" })
+        .AppendHeader(new[]
+        {
+          "Processor",
+          valueInfo?.name ?? "Value",
+          "Deviation"
+        })
         .AppendRows(tValues
           .Take(tContext)
           .Select(MakeRow))
@@ -209,8 +230,13 @@ public class ReportGenerator : IDisposable
 
       return;
 
-      string[] MakeRow((string, double) v) =>
-        new[] { v.Item1, v.Item2.ToString("F2") + valueInfo?.unit };
+      string[] MakeRow((string, double, double) v) =>
+        new[]
+        {
+          v.Item1,
+          v.Item2.ToString("F2") + valueInfo?.unit,
+          v.Item3.ToString("F2") + valueInfo?.unit
+        };
     });
   }