From e62091996ec26b2324aa4733751aaf9e9ad12e11 Mon Sep 17 00:00:00 2001
From: Frederik Petersen <frederik.petersen@sap.com>
Date: Thu, 28 May 2015 15:48:26 +0200
Subject: [PATCH] Added some confidence by datacount calculations to angle
 cluster polar service

---
 .../sailing/polars/mining/PolarDataMiner.java |  8 ++++-
 ...eedRegressionPerAngleClusterProcessor.java | 30 +++++++++++++++----
 2 files changed, 32 insertions(+), 6 deletions(-)

diff --git a/java/com.sap.sailing.polars/src/com/sap/sailing/polars/mining/PolarDataMiner.java b/java/com.sap.sailing.polars/src/com/sap/sailing/polars/mining/PolarDataMiner.java
index a4780d2351f..58c6d535ed6 100755
--- a/java/com.sap.sailing.polars/src/com/sap/sailing/polars/mining/PolarDataMiner.java
+++ b/java/com.sap.sailing.polars/src/com/sap/sailing/polars/mining/PolarDataMiner.java
@@ -326,8 +326,14 @@ public class PolarDataMiner {
                 SpeedWithConfidence<Void> speedWithConfidence;
                 try {
                     int convertedAngle = convertAngleIfNecessary(angle);
-                    speedWithConfidence = speedRegressionPerAngleClusterProcessor.estimateBoatSpeed(boatClass,
+                    SpeedWithConfidence<Void> regressionResult = speedRegressionPerAngleClusterProcessor.estimateBoatSpeed(boatClass,
                             new KnotSpeedImpl(windSpeed), new DegreeBearingImpl(convertedAngle));
+                    if (regressionResult.getConfidence() > 0.1) {
+                        speedWithConfidence = regressionResult;
+                    } else {
+                        // Low confidence. So put in 0 speed for chart
+                        speedWithConfidence = new SpeedWithConfidenceImpl<Void>(new KnotSpeedImpl(0), regressionResult.getConfidence(), null);
+                    }
                 } catch (NotEnoughDataHasBeenAddedException e) {
                     // No data so put in a 0 speed with 0 confidence
                     speedWithConfidence = new SpeedWithConfidenceImpl<Void>(new KnotSpeedImpl(0), 0, null);
diff --git a/java/com.sap.sailing.polars/src/com/sap/sailing/polars/mining/SpeedRegressionPerAngleClusterProcessor.java b/java/com.sap.sailing.polars/src/com/sap/sailing/polars/mining/SpeedRegressionPerAngleClusterProcessor.java
index 5953fde119b..e1fb5b9e1b4 100644
--- a/java/com.sap.sailing.polars/src/com/sap/sailing/polars/mining/SpeedRegressionPerAngleClusterProcessor.java
+++ b/java/com.sap.sailing.polars/src/com/sap/sailing/polars/mining/SpeedRegressionPerAngleClusterProcessor.java
@@ -29,6 +29,8 @@ public class SpeedRegressionPerAngleClusterProcessor implements Processor<Groupe
     private static final Logger logger = Logger.getLogger(CubicRegressionPerCourseProcessor.class.getName());
     
     private final Map<GroupKey, IncrementalLeastSquares> regressions = new HashMap<>();
+    
+    private final Map<BoatClass, Long> fixCountPerBoatClass = new HashMap<>();
 
     private final ClusterGroup<Bearing> angleClusterGroup;
     
@@ -46,6 +48,13 @@ public class SpeedRegressionPerAngleClusterProcessor implements Processor<Groupe
     public void processElement(GroupedDataEntry<GPSFixMovingWithPolarContext> element) {
         GroupKey key = element.getKey();
         IncrementalLeastSquares regression;
+        BoatClass boatClass = element.getDataEntry().getBoatClass();
+        synchronized (fixCountPerBoatClass) {
+            if (!fixCountPerBoatClass.containsKey(boatClass)) {
+                fixCountPerBoatClass.put(boatClass, 0L);
+            }
+            fixCountPerBoatClass.put(boatClass, fixCountPerBoatClass.get(boatClass) + 1);
+        }
         synchronized (regressions) {
             regression = regressions.get(key);
             if (regression == null) {
@@ -66,18 +75,29 @@ public class SpeedRegressionPerAngleClusterProcessor implements Processor<Groupe
     public SpeedWithConfidence<Void> estimateBoatSpeed(BoatClass boatClass, Speed windSpeed, Bearing trueWindAngle) throws NotEnoughDataHasBeenAddedException {
         double speedSum = 0;
         double numberOfSpeeds = 0;
-        for (int i = -5; i <= 5; i++) {
+        long fixCount = 0;
+        for (int i = -2; i <= 2; i++) {
             GroupKey key = createGroupKey(boatClass, new DegreeBearingImpl(Math.abs(trueWindAngle.getDegrees()) + i));
             if (regressions.containsKey(key)) {
-                speedSum += regressions.get(key).getOrCreatePolynomialFunction().value(windSpeed.getKnots());
-                numberOfSpeeds++;
+                IncrementalLeastSquares incrementalLeastSquares = regressions.get(key);
+                fixCount = fixCount + incrementalLeastSquares.getNumberOfAddedPoints();
+                if (fixCount > 10) {
+                    speedSum += incrementalLeastSquares.getOrCreatePolynomialFunction().value(windSpeed.getKnots());
+                    numberOfSpeeds++;
+                }
             } 
         }
-        if (numberOfSpeeds < 1) {
+        fixCount = (long) (fixCount / numberOfSpeeds);
+        long fixCountOverall = 0;
+        if (numberOfSpeeds < 2 || fixCount < 10) {
             throw new NotEnoughDataHasBeenAddedException("Not enough data has been added to Per Course Regressions");
+        } else {
+            synchronized (fixCountPerBoatClass) {
+                fixCountOverall = fixCountPerBoatClass.get(boatClass);
+             }
         }
         Speed speed = new KnotSpeedImpl(speedSum / numberOfSpeeds);
-        return new SpeedWithConfidenceImpl<Void>(speed, /*FIXME*/ 0.5, null);
+        return new SpeedWithConfidenceImpl<Void>(speed, Math.min(1, 5.0 * ((double) fixCount / fixCountOverall)), null);
     }
     
     private GroupKey createGroupKey(final BoatClass boatClass, final Bearing angle) {