[chronojump] Force sensor GetVariabilityAndAccuracy Error (feedback) fixed

[Xavier de Blas <xaviblas src gnome org>]

commit 3887b49feb04b3e69a54b3fb8cb30ce9a4d13063
Author: Xavier de Blas <xaviblas gmail com>
Date:   Fri Jun 7 15:14:08 2019 +0200

    Force sensor GetVariabilityAndAccuracy Error (feedback) fixed

 src/forceSensor.cs            | 27 +++++++++++++++++----------
 src/gui/forceSensorAnalyze.cs |  8 ++++----
 2 files changed, 21 insertions(+), 14 deletions(-)
---
diff --git a/src/forceSensor.cs b/src/forceSensor.cs
index ea024d8c..82888bbf 100644
--- a/src/forceSensor.cs
+++ b/src/forceSensor.cs
@@ -247,7 +247,7 @@ public class ForceSensorCapturePoints
                double elapsedSeconds = times[countB]/1000000.0 - times[countA]/1000000.0;
                return sum * Util.DivideSafe(elapsedSeconds, samples);
        }
-       public void GetVariabilityAndAccuracy(int countA, int countB, int feedbackN, out double variability, 
out double feedbackDifference)
+       public void GetVariabilityAndAccuracy(int countA, int countB, int feedbackF, out double variability, 
out double feedbackDifference)
        {
                if(countA == countB)
                {
@@ -265,17 +265,24 @@ public class ForceSensorCapturePoints
                for(int i = countA; i <= countB; i ++)
                        sum += forces[i];
 
-
                double avg = sum / numSamples;
 
-               // 2) move all the forces to 0 (substracting from average)
-               //    and have them in absolute value
-               double sumAt0 = 0;
+               // 2) Average of the differences between force and average
+               sum = 0;
+               for(int i = countA; i <= countB; i ++)
+                       sum += Math.Abs(forces[i]-avg);
+
+               variability = Util.DivideSafe(sum, numSamples);
+
+               // 3) Calculate difference.
+               // Average of the differences between force and average
+
+               //feedbackDifference = Math.Abs(feedbackF - avg);
+               sum = 0;
                for(int i = countA; i <= countB; i ++)
-                       sumAt0 += Math.Abs(forces[i]-avg);
+                       sum += Math.Abs(forces[i]-feedbackF);
 
-               variability = Util.DivideSafe(sumAt0, numSamples);
-               feedbackDifference = Math.Abs(feedbackN - avg);
+               feedbackDifference = Util.DivideSafe(sum, numSamples);
        }
 
        public int MarginLeft
@@ -871,9 +878,9 @@ public class ForceSensorAnalyzeInstant
        }
 
        public void CalculateVariabilityAndAccuracy(int countA, int countB,
-                       int feedbackN, out double variability, out double feedbackDifference)
+                       int feedbackF, out double variability, out double feedbackDifference)
        {
-               fscAIPoints.GetVariabilityAndAccuracy(countA, countB, feedbackN, out variability, out 
feedbackDifference);
+               fscAIPoints.GetVariabilityAndAccuracy(countA, countB, feedbackF, out variability, out 
feedbackDifference);
        }
        /*
         * Calculates RFD in a point using previous and next point
diff --git a/src/gui/forceSensorAnalyze.cs b/src/gui/forceSensorAnalyze.cs
index a38ac4cb..68f7283a 100644
--- a/src/gui/forceSensorAnalyze.cs
+++ b/src/gui/forceSensorAnalyze.cs
@@ -1003,9 +1003,9 @@ public partial class ChronoJumpWindow
                        // 11) calculate and paint variability
                        double variability = 0;
                        double feedbackDiff = 0;
-                       int feedbackN = Convert.ToInt32(spin_force_sensor_capture_feedback_at.Value);
+                       int feedbackF = Convert.ToInt32(spin_force_sensor_capture_feedback_at.Value);
 
-                       fsAI.CalculateVariabilityAndAccuracy(hscaleLower, hscaleHigher, feedbackN, out 
variability, out feedbackDiff);
+                       fsAI.CalculateVariabilityAndAccuracy(hscaleLower, hscaleHigher, feedbackF, out 
variability, out feedbackDiff);
 
                        layout_force_ai_text.SetMarkup(string.Format("Variability: {0:0.#} N",
                                                Math.Round(variability, 1) ));
@@ -1016,9 +1016,9 @@ public partial class ChronoJumpWindow
                                        layout_force_ai_text);
 
                        // 12) calculate and paint Accuracy (Feedback difference)
-                       if(feedbackN > 0)
+                       if(feedbackF > 0)
                        {
-                               layout_force_ai_text.SetMarkup(string.Format("Accuracy (vs Feedback): {0:0.#} 
N",
+                               layout_force_ai_text.SetMarkup(string.Format("Error (Feedback): {0:0.#} N",
                                                        Math.Round(feedbackDiff, 1) ));
 
                                layout_force_ai_text.GetPixelSize(out textWidth, out textHeight);