From 5546f481c3ae078786714e86c41ea9c19e9a40a0 Mon Sep 17 00:00:00 2001
From: Edwin Jakobs <edwin@rndr.studio>
Date: Sat, 2 Nov 2019 12:50:09 +0100
Subject: [PATCH] Add binding for DoubleArray

---
 .../src/main/kotlin/DataBinding.kt              | 17 +++++++++++++++++
 .../src/main/kotlin/GradientDescent.kt          |  9 +++++++--
 2 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/orx-gradient-descent/src/main/kotlin/DataBinding.kt b/orx-gradient-descent/src/main/kotlin/DataBinding.kt
index 24fdb7b5..9397dbe1 100644
--- a/orx-gradient-descent/src/main/kotlin/DataBinding.kt
+++ b/orx-gradient-descent/src/main/kotlin/DataBinding.kt
@@ -11,6 +11,14 @@ fun <T : Any> modelToArray(model: T): DoubleArray {
     val doubles = mutableListOf<Double>()
     model::class.java.declaredFields.forEach {
         when {
+            it.type == DoubleArray::class.java -> {
+                it.isAccessible = true
+                val da = it.get(model) as DoubleArray
+                for (d in da) {
+                    doubles.add(d)
+                }
+            }
+
             it.type == Double::class.java -> {
                 it.isAccessible = true
                 doubles.add(it.getDouble(model))
@@ -48,6 +56,15 @@ fun <T : Any> arrayToModel(data: DoubleArray, model: T) {
     var index = 0
     model::class.java.declaredFields.forEach {
         when {
+            it.type == DoubleArray::class.java -> {
+                it.isAccessible = true
+                //it.setDouble(model, data[index])
+                val da = it.get(model) as DoubleArray
+                for (i in 0 until da.size) {
+                    da[i] = data[index]
+                    index++
+                }
+            }
             it.type == Double::class.java -> {
                 it.isAccessible = true
                 it.setDouble(model, data[index])
diff --git a/orx-gradient-descent/src/main/kotlin/GradientDescent.kt b/orx-gradient-descent/src/main/kotlin/GradientDescent.kt
index 2a447f2b..53c3d8c3 100644
--- a/orx-gradient-descent/src/main/kotlin/GradientDescent.kt
+++ b/orx-gradient-descent/src/main/kotlin/GradientDescent.kt
@@ -35,6 +35,7 @@ fun max(a: Double, b: Double, c: Double, d: Double, e: Double, f: Double, g: Dou
     return max(max(max(max(max(max(max(a, b), c), d), e), f), g), h)
 }
 
+
 fun gradient(x: DoubleArray, objective: (parameters: DoubleArray) -> Double): DoubleArray {
     var k = 0
     val tempX = x.copyOf()
@@ -83,6 +84,7 @@ private fun add(x: Array<DoubleArray>, y: Array<DoubleArray>) = Array(x.size) {
 private fun sub(x: Array<DoubleArray>, y: Array<DoubleArray>) = Array(x.size) { sub(x[it], y[it]) }
 private fun mul(x: Array<DoubleArray>, y: Double) = Array(x.size) { mul(x[it], y) }
 private fun mul(x: DoubleArray, y: Double) = DoubleArray(x.size) { x[it] * y }
+private fun mul(x: DoubleArray, y: DoubleArray) = DoubleArray(x.size) { x[it] * y[it] }
 private fun div(x: Array<DoubleArray>, y: Double) = Array(x.size) { div(x[it], y) }
 private fun div(x: DoubleArray, y: Double) = DoubleArray(x.size) { x[it] / y }
 private fun norm2(x: DoubleArray): Double {
@@ -96,7 +98,9 @@ fun dot(x: Array<DoubleArray>, y: DoubleArray): DoubleArray = DoubleArray(x.size
 class MinimizationResult(val solution: DoubleArray, val value: Double, val gradient: DoubleArray,
                          val inverseHessian: Array<DoubleArray>, val iterations: Int)
 
-fun minimize(_x0: DoubleArray, endOnLineSearch: Boolean = false, tol: Double = 1e-8, maxIterations: Int = 1000, f: (DoubleArray) -> Double): MinimizationResult {
+fun minimize(_x0: DoubleArray,
+             weights: DoubleArray = DoubleArray(_x0.size) { 1.0 },
+             endOnLineSearch: Boolean = false, tol: Double = 1e-8, maxIterations: Int = 1000, f: (DoubleArray) -> Double): MinimizationResult {
     val grad = { a: DoubleArray -> gradient(a, f) }
     var x0 = _x0.copyOf()
     var g0 = grad(x0)
@@ -175,7 +179,8 @@ fun minimize(_x0: DoubleArray, endOnLineSearch: Boolean = false, tol: Double = 1
 
 fun <T : Any> minimizeModel(model: T, endOnLineSearch: Boolean = false, tol: Double = 1e-8, maxIterations: Int = 1000, function: (T) -> Double) {
     val doubles = modelToArray(model)
-    val solution = minimize(doubles, endOnLineSearch, tol, maxIterations) {
+    val weights = DoubleArray(doubles.size) { 1.0 }
+    val solution = minimize(doubles, weights, endOnLineSearch, tol, maxIterations) {
         arrayToModel(it, model)
         function(model)
     }