normalization of methods

lib/filters/sgf/Sgf.Tests.cs

@@ -44,7 +44,7 @@ public class SgfTests
         // 3. Span Mode
         double[] spanInput = series.Values.ToArray();
         double[] spanOutput = new double[spanInput.Length];
-        Sgf.Calculate(spanInput, spanOutput, period, polyOrder);
+        Sgf.Batch(spanInput, spanOutput, period, polyOrder);
 
         // Assert
         for (int i = 0; i < series.Count; i++)

lib/filters/sgf/Sgf.Validation.Tests.cs

@@ -201,7 +201,7 @@ public class SgfValidationTests : IDisposable
         foreach (var (period, order) in scenarios)
         {
             double[] output = new double[source.Length];
-            Sgf.Calculate(source.AsSpan(), output.AsSpan(), period, order);
+            Sgf.Batch(source.AsSpan(), output.AsSpan(), period, order);
 
             var expected = CalculateExpectedSgf(source, period, order);
 

lib/filters/sgf/Sgf.cs

@@ -177,7 +177,7 @@ public sealed class Sgf : AbstractBase
         }
 
         var resultValues = new double[source.Count];
-        Calculate(source.Values, resultValues, _period, _polyOrder);
+        Batch(source.Values, resultValues, _period, _polyOrder);
 
         var result = new TSeries();
         var times = source.Times;
@@ -197,16 +197,14 @@ public sealed class Sgf : AbstractBase
         return result;
     }
 
-    public override void Prime(ReadOnlySpan<double> source, TimeSpan? step = null)
+    public static TSeries Batch(TSeries source, int period, int polyOrder = 2)
     {
-        foreach (double value in source)
-        {
-            Update(new TValue(DateTime.MinValue, value), isNew: true);
-        }
+        var indicator = new Sgf(period, polyOrder);
+        return indicator.Update(source);
     }
 
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    public static void Calculate(ReadOnlySpan<double> source, Span<double> output, int period, int polyOrder = 2)
+    public static void Batch(ReadOnlySpan<double> source, Span<double> output, int period, int polyOrder = 2)
     {
         if (source.Length != output.Length)
         {
@@ -262,6 +260,21 @@ public sealed class Sgf : AbstractBase
         }
     }
 
+    public override void Prime(ReadOnlySpan<double> source, TimeSpan? step = null)
+    {
+        foreach (double value in source)
+        {
+            Update(new TValue(DateTime.MinValue, value), isNew: true);
+        }
+    }
+
+    public static (TSeries Results, Sgf Indicator) Calculate(TSeries source, int period, int polyOrder = 2)
+    {
+        var indicator = new Sgf(period, polyOrder);
+        TSeries results = indicator.Update(source);
+        return (results, indicator);
+    }
+
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     private static void CalculateWeightsSpan(Span<double> weights, int period, int polyOrder)
     {