add naive impl of pow

Author: devcrocod

multik-default/src/commonMain/kotlin/org/jetbrains/kotlinx/multik/default/linalg/DefaultLinAlg.kt

@@ -6,19 +6,15 @@ package org.jetbrains.kotlinx.multik.default.linalg
 
 import org.jetbrains.kotlinx.multik.api.linalg.LinAlg
 import org.jetbrains.kotlinx.multik.api.linalg.LinAlgEx
-import org.jetbrains.kotlinx.multik.kotlin.linalg.KELinAlg
 import org.jetbrains.kotlinx.multik.ndarray.data.D2
 import org.jetbrains.kotlinx.multik.ndarray.data.MultiArray
 import org.jetbrains.kotlinx.multik.ndarray.data.NDArray
 
-public object DefaultLinAlg : LinAlg {
+public expect object DefaultLinAlg : LinAlg {
 
     override val linAlgEx: LinAlgEx
-        get() = DefaultLinAlgEx
 
-    override fun <T : Number> pow(mat: MultiArray<T, D2>, n: Int): NDArray<T, D2> {
-        return KELinAlg.pow(mat, n)
-    }
+    override fun <T : Number> pow(mat: MultiArray<T, D2>, n: Int): NDArray<T, D2>
 
-    override fun <T : Number> norm(mat: MultiArray<T, D2>, p: Int): Double = KELinAlg.norm(mat, p)
+    override fun <T : Number> norm(mat: MultiArray<T, D2>, p: Int): Double
 }

multik-default/src/iosMain/kotlin/org.jetbrains.kotlinx.multik.default/linalg/DefaultLinAlg.kt

@@ -0,0 +1,22 @@
+/*
+ * Copyright 2020-2022 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license.
+ */
+
+package org.jetbrains.kotlinx.multik.default.linalg
+
+import org.jetbrains.kotlinx.multik.api.linalg.LinAlg
+import org.jetbrains.kotlinx.multik.api.linalg.LinAlgEx
+import org.jetbrains.kotlinx.multik.kotlin.linalg.KELinAlg
+import org.jetbrains.kotlinx.multik.ndarray.data.D2
+import org.jetbrains.kotlinx.multik.ndarray.data.MultiArray
+import org.jetbrains.kotlinx.multik.ndarray.data.NDArray
+
+public actual object DefaultLinAlg : LinAlg {
+
+    actual override val linAlgEx: LinAlgEx
+        get() = DefaultLinAlgEx
+
+    actual override fun <T : Number> pow(mat: MultiArray<T, D2>, n: Int): NDArray<T, D2> = KELinAlg.pow(mat, n)
+
+    actual override fun <T : Number> norm(mat: MultiArray<T, D2>, p: Int): Double = KELinAlg.norm(mat, p)
+}

multik-default/src/jsMain/kotlin/org.jetbrains.kotlinx.multik.default/linalg/DefaultLinAlg.kt

@@ -0,0 +1,22 @@
+/*
+ * Copyright 2020-2022 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license.
+ */
+
+package org.jetbrains.kotlinx.multik.default.linalg
+
+import org.jetbrains.kotlinx.multik.api.linalg.LinAlg
+import org.jetbrains.kotlinx.multik.api.linalg.LinAlgEx
+import org.jetbrains.kotlinx.multik.kotlin.linalg.KELinAlg
+import org.jetbrains.kotlinx.multik.ndarray.data.D2
+import org.jetbrains.kotlinx.multik.ndarray.data.MultiArray
+import org.jetbrains.kotlinx.multik.ndarray.data.NDArray
+
+public actual object DefaultLinAlg : LinAlg {
+
+    actual override val linAlgEx: LinAlgEx
+        get() = DefaultLinAlgEx
+
+    actual override fun <T : Number> pow(mat: MultiArray<T, D2>, n: Int): NDArray<T, D2> = KELinAlg.pow(mat, n)
+
+    actual override fun <T : Number> norm(mat: MultiArray<T, D2>, p: Int): Double = KELinAlg.norm(mat, p)
+}

multik-default/src/jvmMain/kotlin/org/jetbrains/kotlinx/multik/default/linalg/DefaultLinAlg.kt

@@ -0,0 +1,22 @@
+/*
+ * Copyright 2020-2022 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license.
+ */
+
+package org.jetbrains.kotlinx.multik.default.linalg
+
+import org.jetbrains.kotlinx.multik.api.linalg.LinAlg
+import org.jetbrains.kotlinx.multik.api.linalg.LinAlgEx
+import org.jetbrains.kotlinx.multik.kotlin.linalg.KELinAlg
+import org.jetbrains.kotlinx.multik.ndarray.data.D2
+import org.jetbrains.kotlinx.multik.ndarray.data.MultiArray
+import org.jetbrains.kotlinx.multik.ndarray.data.NDArray
+import org.jetbrains.kotlinx.multik.openblas.linalg.NativeLinAlg
+
+public actual object DefaultLinAlg : LinAlg {
+    actual override val linAlgEx: LinAlgEx
+        get() = DefaultLinAlgEx
+
+    actual override fun <T : Number> pow(mat: MultiArray<T, D2>, n: Int): NDArray<T, D2> = NativeLinAlg.pow(mat, n)
+
+    actual override fun <T : Number> norm(mat: MultiArray<T, D2>, p: Int): Double = KELinAlg.norm(mat)
+}

multik-default/src/nativeMain/kotlin/org.jetbrains.kotlinx.multik.default/linalg/DefaultLinAlg.kt

@@ -0,0 +1,22 @@
+/*
+ * Copyright 2020-2022 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license.
+ */
+
+package org.jetbrains.kotlinx.multik.default.linalg
+
+import org.jetbrains.kotlinx.multik.api.linalg.LinAlg
+import org.jetbrains.kotlinx.multik.api.linalg.LinAlgEx
+import org.jetbrains.kotlinx.multik.kotlin.linalg.KELinAlg
+import org.jetbrains.kotlinx.multik.ndarray.data.D2
+import org.jetbrains.kotlinx.multik.ndarray.data.MultiArray
+import org.jetbrains.kotlinx.multik.ndarray.data.NDArray
+import org.jetbrains.kotlinx.multik.openblas.linalg.NativeLinAlg
+
+public actual object DefaultLinAlg : LinAlg {
+    actual override val linAlgEx: LinAlgEx
+        get() = DefaultLinAlgEx
+
+    actual override fun <T : Number> pow(mat: MultiArray<T, D2>, n: Int): NDArray<T, D2> = NativeLinAlg.pow(mat, n)
+
+    actual override fun <T : Number> norm(mat: MultiArray<T, D2>, p: Int): Double = KELinAlg.norm(mat)
+}

multik-openblas/src/commonMain/kotlin/org/jetbrains/kotlinx/multik/openblas/linalg/NativeLinAlg.kt

@@ -18,7 +18,14 @@ public object NativeLinAlg : LinAlg {
         get() = NativeLinAlgEx
 
     override fun <T : Number> pow(mat: MultiArray<T, D2>, n: Int): NDArray<T, D2> {
-        TODO("Not yet implemented")
+        requireSquare(mat.shape)
+        if (n == 0) return mk.identity(mat.shape[0], mat.dtype)
+        return if (n % 2 == 0) {
+            val tmp = pow(mat, n / 2)
+            NativeLinAlgEx.dotMM(tmp, tmp)
+        } else {
+            NativeLinAlgEx.dotMM(mat, pow(mat, n - 1))
+        }
     }
 
     override fun <T : Number> norm(mat: MultiArray<T, D2>, p: Int): Double {

multik-openblas/src/commonMain/kotlin/org/jetbrains/kotlinx/multik/openblas/linalg/NativeLinAlgEx.kt

@@ -357,6 +357,6 @@ private fun requireDotShape(aShape: IntArray, bShape: IntArray) = require(aShape
 }
 
 
-private fun requireSquare(shape: IntArray) = require(shape[0] == shape[1]) {
+internal fun requireSquare(shape: IntArray) = require(shape[0] == shape[1]) {
     "Ndarray must be square: shape = ${shape.joinToString(",", "(", ")")}"
 }