First draft for optimal duration computation, add apache math dependency

app/build.gradle

@@ -138,6 +138,9 @@ dependencies {
     // CSV Parser: https://mvnrepository.com/artifact/org.apache.commons/commons-csv
     implementation 'org.apache.commons:commons-csv:1.7'
 
+    // Polynomial Regression
+    implementation 'org.apache.commons:commons-math3:3.6.1'
+
     // Instrumented Tests
     androidTestImplementation 'androidx.test:core:1.2.0'
     androidTestImplementation 'androidx.test:runner:1.2.0'

app/src/main/java/net/pokeranalytics/android/calculus/Calculator.kt

@@ -21,6 +21,8 @@ import net.pokeranalytics.android.util.extensions.startOfDay
 import java.util.*
 import kotlin.math.max
 import kotlin.math.min
+import kotlin.math.pow
+import kotlin.math.sqrt
 
 /**
  * The class performing statIds computation
@@ -119,7 +121,7 @@ class Calculator {
 		val computeStandardDeviation: Boolean
 			get() {
 				this.stats.forEach {
-					if (it == STANDARD_DEVIATION_BB_PER_100_HANDS || it == STANDARD_DEVIATION || it == STANDARD_DEVIATION_HOURLY) {
+					if (it.isStandardDeviation) {
 						return true
 					}
 				}
@@ -335,6 +337,11 @@ class Calculator {
 					)
 				)
 			}
+			var averageBB = 0.0
+			if (bbSessionCount > 0) {
+				averageBB = bbSum / bbSessionCount
+				results.addStat(AVERAGE_NET_BB, averageBB)
+			}
 
 			val shouldIterateOverComputables =
 				(options.progressValues == Options.ProgressValues.STANDARD || options.computeLongestStreak)
@@ -561,15 +568,19 @@ class Calculator {
 
 				// Session
 				var stdSum = 0.0
+				var stdBBSum = 0.0
 				var stdBBper100HandsSum = 0.0
 				computables.forEach { session ->
-					stdSum += Math.pow(session.ratedNet - average, 2.0)
-					stdBBper100HandsSum += Math.pow(session.bbPer100Hands - bbPer100Hands, 2.0)
+					stdSum += (session.ratedNet - average).pow(2.0)
+					stdBBSum += (session.bbNet - averageBB).pow(2.0)
+					stdBBper100HandsSum += (session.bbPer100Hands - bbPer100Hands).pow(2.0)
 				}
-				val standardDeviation = Math.sqrt(stdSum / computables.size)
-				val standardDeviationBBper100Hands = Math.sqrt(stdBBper100HandsSum / computables.size)
+				val standardDeviation = sqrt(stdSum / computables.size)
+				val standardDeviationBB = sqrt(stdBBSum / computables.size)
+				val standardDeviationBBper100Hands = sqrt(stdBBper100HandsSum / computables.size)
 
 				results.addStat(STANDARD_DEVIATION, standardDeviation)
+				results.addStat(STANDARD_DEVIATION_BB, standardDeviationBB)
 				results.addStat(STANDARD_DEVIATION_BB_PER_100_HANDS, standardDeviationBBper100Hands)
 
 				// Session Set
@@ -578,9 +589,9 @@ class Calculator {
 					sessionSets.forEach { set ->
 						val ssStats = SSStats(set, computableGroup.query)
 						val sHourlyRate = ssStats.hourlyRate
-						hourlyStdSum += Math.pow(sHourlyRate - hourlyRate, 2.0)
+						hourlyStdSum += (sHourlyRate - hourlyRate).pow(2.0)
 					}
-					val hourlyStandardDeviation = Math.sqrt(hourlyStdSum / sessionSets.size)
+					val hourlyStandardDeviation = sqrt(hourlyStdSum / sessionSets.size)
 
 					results.addStat(STANDARD_DEVIATION_HOURLY, hourlyStandardDeviation)
 				}

app/src/main/java/net/pokeranalytics/android/calculus/Stat.kt

@@ -52,6 +52,7 @@ enum class Stat(override var uniqueIdentifier: Int) : IntIdentifiable, RowRepres
 	BB_SESSION_COUNT(26),
 	TOTAL_BUYIN(27),
 	RISK_OF_RUIN(28),
+	STANDARD_DEVIATION_BB(29),
 	;
 
 	companion object : IntSearchable<Stat> {
@@ -119,6 +120,7 @@ enum class Stat(override var uniqueIdentifier: Int) : IntIdentifiable, RowRepres
 				STANDARD_DEVIATION -> R.string.standard_deviation
 				STANDARD_DEVIATION_HOURLY -> R.string.standard_deviation_per_hour
 				STANDARD_DEVIATION_BB_PER_100_HANDS -> R.string.standard_deviation_bb_per_100_hands
+				STANDARD_DEVIATION_BB -> R.string.bb_standard_deviation
 				HANDS_PLAYED -> R.string.number_of_hands
 				LOCATIONS_PLAYED -> R.string.locations_played
 				LONGEST_STREAKS -> R.string.longest_streaks
@@ -169,7 +171,7 @@ enum class Stat(override var uniqueIdentifier: Int) : IntIdentifiable, RowRepres
 			}
 			// white amountsr
 			AVERAGE_BUYIN, STANDARD_DEVIATION, STANDARD_DEVIATION_HOURLY,
-			STANDARD_DEVIATION_BB_PER_100_HANDS, TOTAL_BUYIN -> {
+			STANDARD_DEVIATION_BB_PER_100_HANDS, STANDARD_DEVIATION_BB, TOTAL_BUYIN -> {
 				return TextFormat(value.toCurrency(currency))
 			}
 			LONGEST_STREAKS -> {
@@ -200,6 +202,7 @@ enum class Stat(override var uniqueIdentifier: Int) : IntIdentifiable, RowRepres
 			NUMBER_OF_GAMES -> R.string.number_of_records
 			NET_RESULT -> R.string.total
 			STANDARD_DEVIATION -> R.string.net_result
+			STANDARD_DEVIATION_BB -> R.string.average_net_result_bb_
 			STANDARD_DEVIATION_HOURLY -> R.string.hour_rate_without_pauses
 			STANDARD_DEVIATION_BB_PER_100_HANDS -> R.string.net_result_bb_per_100_hands
 			WIN_RATIO, HOURLY_DURATION -> return this.localizedTitle(context)
@@ -235,12 +238,21 @@ enum class Stat(override var uniqueIdentifier: Int) : IntIdentifiable, RowRepres
 	val hasProgressGraph: Boolean
 		get() {
 			return when (this) {
-				HOURLY_DURATION, AVERAGE_HOURLY_DURATION,
+				HOURLY_DURATION, AVERAGE_HOURLY_DURATION, STANDARD_DEVIATION_BB,
 				STANDARD_DEVIATION, STANDARD_DEVIATION_HOURLY, STANDARD_DEVIATION_BB_PER_100_HANDS -> false
 				else -> true
 			}
 		}
 
+	val isStandardDeviation: Boolean
+		get() {
+			return when (this) {
+				STANDARD_DEVIATION, STANDARD_DEVIATION_BB,
+				STANDARD_DEVIATION_HOURLY, STANDARD_DEVIATION_BB_PER_100_HANDS -> true
+				else -> false
+			}
+		}
+
 
 	val legendHideRightValue: Boolean
 		get() {

app/src/main/java/net/pokeranalytics/android/calculus/optimalduration/OptimalDurationCalculator.kt

@@ -1,2 +1,125 @@
 package net.pokeranalytics.android.calculus.optimalduration
 
+import io.realm.Realm
+import net.pokeranalytics.android.calculus.Calculator
+import net.pokeranalytics.android.calculus.Stat
+import net.pokeranalytics.android.exceptions.PAIllegalStateException
+import net.pokeranalytics.android.model.filter.Query
+import net.pokeranalytics.android.model.filter.QueryCondition
+import net.pokeranalytics.android.model.realm.Session
+import org.apache.commons.math3.fitting.PolynomialCurveFitter
+import org.apache.commons.math3.fitting.WeightedObservedPoints
+import java.util.*
+import kotlin.math.pow
+
+class OptimalDurationCalculator {
+
+	companion object {
+
+		fun start(session: Session, completion: (Double) -> (Unit)) {
+
+			if (!session.isCashGame()) {
+				throw PAIllegalStateException("this only makes sense for cash game sessions")
+			}
+
+			val realm = Realm.getDefaultInstance()
+
+			val isLive = session.bankroll?.live ?: true
+
+			val query = Query().add(QueryCondition.IsCash) // cash game
+			query.add(if (isLive) { QueryCondition.IsLive } else { QueryCondition.IsOnline }) // live / online
+			query.add(QueryCondition.EndDateNotNull) // ended
+			query.add(QueryCondition.BigBlindNotNull) // has BB value
+
+			val sessions = query.queryWith(realm.where(Session::class.java)).findAll()
+			val sessionsByDuration = sessions.groupBy {
+				it.netDuration // TODO select a value per 15 min or something...
+			}
+
+			// define if we have enough sessions
+			if (sessions.size < 50) {
+				return
+			}
+
+			val options = Calculator.Options()
+			options.query = query
+			val report = Calculator.computeStats(realm, options)
+			val stdBB = report.results.firstOrNull()?.computedStat(Stat.STANDARD_DEVIATION_BB)?.value
+
+			val p = polynomialRegression(sessions, stdBB)
+
+			var bestAverage = 0.0
+			var bestHourlyRate = 0.0
+			var bestDuration = 0.0
+			var maxDuration = 0.0
+
+			sessionsByDuration.keys.forEach {
+
+				val duration = it.toDouble()
+				if (duration < 0) { // TODO define whats valid
+					return
+				}
+
+				val averageResult = getBB(duration, p)
+				val hourly = averageResult / duration
+				if (averageResult > bestAverage && hourly > 2 / 3 * bestHourlyRate) {
+					bestAverage = averageResult
+					bestDuration = duration
+				}
+
+				if (duration > 0 && hourly > bestHourlyRate) {
+					bestHourlyRate = hourly
+				}
+				if (duration > maxDuration){
+					maxDuration = duration
+				}
+
+			}
+
+			if (bestDuration > 0.0) {
+				completion(bestDuration)
+			}
+
+			realm.close()
+
+		}
+
+		private fun getBB(netDuration: Double, polynomial: DoubleArray): Double {
+			var y = 0.0
+			for (i in polynomial.indices) {
+				y += polynomial[i] * netDuration.pow(i)
+			}
+			return y
+		}
+
+		private fun polynomialRegression(sessions: List<Session>, bbStandardDeviation: Double?): DoubleArray {
+
+			val stdBB = bbStandardDeviation ?: Double.MAX_VALUE
+
+			val points = WeightedObservedPoints()
+			val now = Date().time
+
+			sessions.forEach {
+				var weight = 5.0
+
+				val endTime = it.endDate?.time ?: 0L
+
+				val age = now - endTime
+				if (age > 2 * 365 * 24 * 3600 * 1000L) { // if more than 2 years loses 1 point
+					weight -= 1.0
+				}
+				if (it.bbNet > 2 * stdBB) { // if very big result loses 3 points
+					weight -= 3.0
+				}
+
+				points.add(weight, it.netDuration.toDouble(), it.bbNet)
+
+			}
+
+			// polynomial of 7 degree, same as iOS
+			return PolynomialCurveFitter.create(7).fit(points.toList())
+		}
+
+	}
+
+}

app/src/main/java/net/pokeranalytics/android/model/realm/ComputableResult.kt

@@ -6,19 +6,19 @@ import net.pokeranalytics.android.model.filter.QueryCondition
 
 open class ComputableResult() : RealmObject(), Filterable {
 
-	 var ratedNet: Double = 0.0
+	var ratedNet: Double = 0.0
 
-	 var bbNet: BB = 0.0
+	var bbNet: BB = 0.0
 
-	 var hasBigBlind: Int = 0
+	var hasBigBlind: Int = 0
 
-	 var isPositive: Int = 0
+	var isPositive: Int = 0
 
-	 var ratedBuyin: Double = 0.0
+	var ratedBuyin: Double = 0.0
 
-	 var estimatedHands: Double = 0.0
+	var estimatedHands: Double = 0.0
 
-	 var bbPer100Hands: BB = 0.0
+	var bbPer100Hands: BB = 0.0
 
 	var session: Session? = null
 
@@ -35,7 +35,8 @@ open class ComputableResult() : RealmObject(), Filterable {
 		this.bbNet = session.bbNet
 		this.hasBigBlind = if (session.cgBigBlind != null) 1 else 0
 		this.estimatedHands = session.estimatedHands
-		this.bbPer100Hands = session.bbNet / (session.numberOfHandsPerHour * session.hourlyDuration) * 100
+		this.bbPer100Hands =
+			session.bbNet / (session.numberOfHandsPerHour * session.hourlyDuration) * 100
 
 	}
 
@@ -51,11 +52,11 @@ open class ComputableResult() : RealmObject(), Filterable {
 
 	companion object {
 
-		fun fieldNameForQueryType(queryCondition: Class < out QueryCondition >): String? {
-            Session.fieldNameForQueryType(queryCondition)?.let {
-                return "session.$it"
-            }
-            return null
+		fun fieldNameForQueryType(queryCondition: Class<out QueryCondition>): String? {
+			Session.fieldNameForQueryType(queryCondition)?.let {
+				return "session.$it"
+			}
+			return null
 		}
 
 	}

app/src/main/java/net/pokeranalytics/android/model/realm/Session.kt

@@ -116,6 +116,8 @@ open class Session : RealmObject(), Savable, Editable, StaticRowRepresentableDat
                 CustomFieldAmountQuery::class.java, CustomFieldNumberQuery::class.java -> "customFieldEntries.numericValue"
                 CustomFieldQuery::class.java -> "customFieldEntries.customFields.id"
 	            DateNotNull::class.java -> "startDate"
+	            EndDateNotNull::class.java -> "endDate"
+	            BigBlindNotNull::class.java -> "cgBigBlind"
                 else -> null
 			}
 		}