Added equality to matrices

kmath-core/src/commonMain/kotlin/scientifik/kmath/linear/Matrix.kt

@@ -152,25 +152,16 @@ interface Matrix<T : Any> : NDStructure<T> {
 /**
  * Diagonal matrix of ones. The matrix is virtual no actual matrix is created
  */
-fun <T : Any, R : Ring<T>> MatrixContext<T, R>.one(rows: Int, columns: Int): Matrix<T> {
-    return object : Matrix<T> {
-        override val rowNum: Int get() = rows
-        override val colNum: Int get() = columns
-        override val features: Set<MatrixFeature> get() = setOf(DiagonalFeature, UnitFeature)
-        override fun get(i: Int, j: Int): T = if (i == j) elementContext.one else elementContext.zero
-    }
+fun <T : Any, R : Ring<T>> MatrixContext<T, R>.one(rows: Int, columns: Int): Matrix<T>  = VirtualMatrix<T>(rows,columns){i, j->
+    if (i == j) elementContext.one else elementContext.zero
 }
 
+
 /**
  * A virtual matrix of zeroes
  */
-fun <T : Any, R : Ring<T>> MatrixContext<T, R>.zero(rows: Int, columns: Int): Matrix<T> {
-    return object : Matrix<T> {
-        override val rowNum: Int get() = rows
-        override val colNum: Int get() = columns
-        override val features: Set<MatrixFeature> get() = setOf(ZeroFeature)
-        override fun get(i: Int, j: Int): T = elementContext.zero
-    }
+fun <T : Any, R : Ring<T>> MatrixContext<T, R>.zero(rows: Int, columns: Int): Matrix<T>  = VirtualMatrix<T>(rows,columns){i, j->
+    elementContext.zero
 }
 
 

kmath-core/src/commonMain/kotlin/scientifik/kmath/linear/StructureMatrix.kt

@@ -23,7 +23,7 @@ class StructureMatrixContext<T : Any, R : Ring<T>>(
     override fun point(size: Int, initializer: (Int) -> T): Point<T> = bufferFactory(size, initializer)
 }
 
-data class StructureMatrix<T : Any>(
+class StructureMatrix<T : Any>(
     val structure: NDStructure<T>,
     override val features: Set<MatrixFeature> = emptySet()
 ) : Matrix<T> {
@@ -47,4 +47,21 @@ data class StructureMatrix<T : Any>(
     override fun get(i: Int, j: Int): T = structure[i, j]
 
     override fun elements(): Sequence<Pair<IntArray, T>> = structure.elements()
+
+    override fun equals(other: Any?): Boolean {
+        if (this === other) return true
+        return when (other) {
+            is StructureMatrix<*> -> return this.structure == other.structure
+            is Matrix<*> -> elements().all { (index, value) -> value == other[index] }
+            else -> false
+        }
+    }
+
+    override fun hashCode(): Int {
+        var result = structure.hashCode()
+        result = 31 * result + features.hashCode()
+        return result
+    }
+
+
 }

kmath-core/src/commonMain/kotlin/scientifik/kmath/linear/VirtualMatrix.kt

@@ -7,4 +7,24 @@ class VirtualMatrix<T : Any>(
     val generator: (i: Int, j: Int) -> T
 ) : Matrix<T> {
     override fun get(i: Int, j: Int): T = generator(i, j)
+
+    override fun equals(other: Any?): Boolean {
+        if (this === other) return true
+        if (other !is Matrix<*>) return false
+
+        if (rowNum != other.rowNum) return false
+        if (colNum != other.colNum) return false
+
+        return elements().all { (index, value) -> value == other[index] }
+    }
+
+    override fun hashCode(): Int {
+        var result = rowNum
+        result = 31 * result + colNum
+        result = 31 * result + features.hashCode()
+        result = 31 * result + generator.hashCode()
+        return result
+    }
+
+
 }

kmath-core/src/commonTest/kotlin/scientifik/kmath/linear/RealLUSolverTest.kt

@@ -14,7 +14,7 @@ class RealLUSolverTest {
 //    @Test
 //    fun testInvert() {
 //        val matrix = realMatrix(2,2){}
-//        val inverted = RealLUSolver.inverse(matrix)
-//        assertTrue { Matrix.equals(matrix,inverted) }
+//        val inverted = LUSolver.real.inverse(matrix)
+//        assertEquals(matrix, inverted)
 //    }
 }