From 1c7bd05c584528cf569aa5f7f537c056e89e4a6e Mon Sep 17 00:00:00 2001
From: Alexander Nozik <altavir@gmail.com>
Date: Tue, 19 Jan 2021 22:48:43 +0300
Subject: [PATCH] Add proper equality check for EJML matrices

---
 .../kscience/kmath/linear/BufferMatrix.kt     |  2 +-
 .../kscience/kmath/structures/NDStructure.kt  |  4 ++--
 .../kmath/structures/LazyNDStructure.kt       |  2 +-
 .../kotlin/kscience/kmath/ejml/EjmlMatrix.kt  | 19 +++++++++++++++----
 4 files changed, 19 insertions(+), 8 deletions(-)

diff --git a/kmath-core/src/commonMain/kotlin/kscience/kmath/linear/BufferMatrix.kt b/kmath-core/src/commonMain/kotlin/kscience/kmath/linear/BufferMatrix.kt
index 80460baca..a74d948fc 100644
--- a/kmath-core/src/commonMain/kotlin/kscience/kmath/linear/BufferMatrix.kt
+++ b/kmath-core/src/commonMain/kotlin/kscience/kmath/linear/BufferMatrix.kt
@@ -43,7 +43,7 @@ public class BufferMatrix<T : Any>(
         if (this === other) return true
 
         return when (other) {
-            is NDStructure<*> -> NDStructure.equals(this, other)
+            is NDStructure<*> -> NDStructure.contentEquals(this, other)
             else -> false
         }
     }
diff --git a/kmath-core/src/commonMain/kotlin/kscience/kmath/structures/NDStructure.kt b/kmath-core/src/commonMain/kotlin/kscience/kmath/structures/NDStructure.kt
index 64e723581..e7d89ca7e 100644
--- a/kmath-core/src/commonMain/kotlin/kscience/kmath/structures/NDStructure.kt
+++ b/kmath-core/src/commonMain/kotlin/kscience/kmath/structures/NDStructure.kt
@@ -54,7 +54,7 @@ public interface NDStructure<T> {
         /**
          * Indicates whether some [NDStructure] is equal to another one.
          */
-        public fun equals(st1: NDStructure<*>, st2: NDStructure<*>): Boolean {
+        public fun contentEquals(st1: NDStructure<*>, st2: NDStructure<*>): Boolean {
             if (st1 === st2) return true
 
             // fast comparison of buffers if possible
@@ -275,7 +275,7 @@ public abstract class NDBuffer<T> : NDStructure<T> {
     override fun elements(): Sequence<Pair<IntArray, T>> = strides.indices().map { it to this[it] }
 
     override fun equals(other: Any?): Boolean {
-        return NDStructure.equals(this, other as? NDStructure<*> ?: return false)
+        return NDStructure.contentEquals(this, other as? NDStructure<*> ?: return false)
     }
 
     override fun hashCode(): Int {
diff --git a/kmath-coroutines/src/jvmMain/kotlin/kscience/kmath/structures/LazyNDStructure.kt b/kmath-coroutines/src/jvmMain/kotlin/kscience/kmath/structures/LazyNDStructure.kt
index bb0d19c23..7aa746797 100644
--- a/kmath-coroutines/src/jvmMain/kotlin/kscience/kmath/structures/LazyNDStructure.kt
+++ b/kmath-coroutines/src/jvmMain/kotlin/kscience/kmath/structures/LazyNDStructure.kt
@@ -24,7 +24,7 @@ public class LazyNDStructure<T>(
     }
 
     public override fun equals(other: Any?): Boolean {
-        return NDStructure.equals(this, other as? NDStructure<*> ?: return false)
+        return NDStructure.contentEquals(this, other as? NDStructure<*> ?: return false)
     }
 
     public override fun hashCode(): Int {
diff --git a/kmath-ejml/src/main/kotlin/kscience/kmath/ejml/EjmlMatrix.kt b/kmath-ejml/src/main/kotlin/kscience/kmath/ejml/EjmlMatrix.kt
index 1c2ded447..82a5399fd 100644
--- a/kmath-ejml/src/main/kotlin/kscience/kmath/ejml/EjmlMatrix.kt
+++ b/kmath-ejml/src/main/kotlin/kscience/kmath/ejml/EjmlMatrix.kt
@@ -3,6 +3,7 @@ package kscience.kmath.ejml
 import kscience.kmath.linear.*
 import kscience.kmath.misc.UnstableKMathAPI
 import kscience.kmath.structures.Matrix
+import kscience.kmath.structures.NDStructure
 import kscience.kmath.structures.RealBuffer
 import org.ejml.dense.row.factory.DecompositionFactory_DDRM
 import org.ejml.simple.SimpleMatrix
@@ -15,7 +16,7 @@ import kotlin.reflect.cast
  * @property origin the underlying [SimpleMatrix].
  * @author Iaroslav Postovalov
  */
-public inline class EjmlMatrix(
+public class EjmlMatrix(
     public val origin: SimpleMatrix,
 ) : Matrix<Double> {
     public override val rowNum: Int get() = origin.numRows()
@@ -49,7 +50,7 @@ public inline class EjmlMatrix(
             override val q: Matrix<Double> by lazy { EjmlMatrix(SimpleMatrix(qr.getQ(null, false))) }
             override val r: Matrix<Double> by lazy { EjmlMatrix(SimpleMatrix(qr.getR(null, false))) }
         }
-        CholeskyDecompositionFeature::class ->         object : CholeskyDecompositionFeature<Double> {
+        CholeskyDecompositionFeature::class -> object : CholeskyDecompositionFeature<Double> {
             override val l: Matrix<Double> by lazy {
                 val cholesky =
                     DecompositionFactory_DDRM.chol(rowNum, true).apply { decompose(origin.ddrm.copy()) }
@@ -57,7 +58,7 @@ public inline class EjmlMatrix(
                 EjmlMatrix(SimpleMatrix(cholesky.getT(null))) + LFeature
             }
         }
-        LupDecompositionFeature::class ->         object : LupDecompositionFeature<Double> {
+        LupDecompositionFeature::class -> object : LupDecompositionFeature<Double> {
             private val lup by lazy {
                 DecompositionFactory_DDRM.lu(origin.numRows(), origin.numCols()).apply { decompose(origin.ddrm.copy()) }
             }
@@ -73,7 +74,17 @@ public inline class EjmlMatrix(
             override val p: Matrix<Double> by lazy { EjmlMatrix(SimpleMatrix(lup.getRowPivot(null))) }
         }
         else -> null
-    }?.let{type.cast(it)}
+    }?.let { type.cast(it) }
 
     public override operator fun get(i: Int, j: Int): Double = origin[i, j]
+
+    override fun equals(other: Any?): Boolean {
+        if (this === other) return true
+        if (other !is Matrix<*>) return false
+        return NDStructure.contentEquals(this, other)
+    }
+
+    override fun hashCode(): Int = origin.hashCode()
+
+
 }