#91 store sample delta instead of calculating it because this changes…

… when the sample reaches the end of the sampling period, thereby changing the value that is removed from the MeanCalculator for the delta, resulting in inflated results.
drmason789 · Apr 30, 2022 · 98d2b0a · 98d2b0a
1 parent 72d275b
commit 98d2b0a
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Showing 2 changed files with 10 additions and 10 deletions.
diff --git a/Trixter.XDream.API/Filters/MeanValueFilterBase.cs b/Trixter.XDream.API/Filters/MeanValueFilterBase.cs
@@ -76,7 +76,7 @@ public MeanValueFilterBase(int periodMilliseconds)
         public void Add(double value, DateTimeOffset timestamp)
         {
             double t = GetSampleTime(timestamp);
-            Sample newSample = new Sample(t, value);
+            Sample newSample = new Sample(t, value, value-this.samples.Latest?.Value);
             this.samples.Add(newSample);
             this.Add(newSample);
             this.Trim(t);
@@ -85,13 +85,12 @@ public void Add(double value, DateTimeOffset timestamp)
             this.ClearCachedValues();
         }
 
-        public void AddDelta(int delta, DateTimeOffset timestamp)
+        public void AddDelta(double delta, DateTimeOffset timestamp)
         {
             if (this.samples.Count == 0)
                 throw new InvalidOperationException("Adding a delta requires an existing sample value.");
 
-            double x = this.samples.Latest.Value + delta;
-            this.Add(x, timestamp);
+            this.Add(this.samples.Latest.Value + delta, timestamp);
         }
 
         /// <summary>

diff --git a/Trixter.XDream.API/Filters/Sample.cs b/Trixter.XDream.API/Filters/Sample.cs
@@ -11,7 +11,8 @@ internal class Sample
         protected Sample previous, next;
 
         public double Value;
-        public double? Delta => this.Value - this.previous?.Value;
+        public double? Delta;
+
         public double T;
 
         public double WeightedValue => this.Value * this.dT;
@@ -23,16 +24,15 @@ public Sample Previous
         {
             get => this.previous;
             set
-            {
-
+            {                
                 if (value != null)
                 {
                     if (value.Next != null)
                         throw new InvalidOperationException("Next sample already set.");
                     else
                         value.next = this;
                 }
-                this.previous = value;
+                this.previous = value;                
             }
         }
         public Sample Next
@@ -52,9 +52,10 @@ public Sample Next
         }
 
 
-        public Sample(double t, double v)
+        public Sample(double t, double v, double? dv)
         {
-            this.Value = v;           
+            this.Value = v;
+            this.Delta = dv;
 
             this.T = t;
         }