diff --git a/examples/build.gradle.kts b/examples/build.gradle.kts
index 3d193efce..f0161afbb 100644
--- a/examples/build.gradle.kts
+++ b/examples/build.gradle.kts
@@ -26,9 +26,13 @@ dependencies {
     implementation(project(":kmath-prob"))
     implementation(project(":kmath-viktor"))
     implementation(project(":kmath-dimensions"))
+    implementation(project(":kmath-nd4j"))
     implementation("org.jetbrains.kotlinx:kotlinx-io-jvm:0.2.0-npm-dev-6")
     implementation("org.jetbrains.kotlinx:kotlinx.benchmark.runtime:0.2.0-dev-20")
-    "benchmarksCompile"(sourceSets.main.get().output + sourceSets.main.get().compileClasspath) //sourceSets.main.output + sourceSets.main.runtimeClasspath
+    implementation("org.slf4j:slf4j-simple:1.7.30")
+    implementation("org.nd4j:nd4j-native-platform:1.0.0-beta7")
+    "benchmarksImplementation"("org.jetbrains.kotlinx:kotlinx.benchmark.runtime-jvm:0.2.0-dev-8")
+    "benchmarksImplementation"(sourceSets.main.get().output + sourceSets.main.get().runtimeClasspath)
 }
 
 // Configure benchmark
diff --git a/kmath-core/src/commonMain/kotlin/kscience/kmath/structures/BoxingNDField.kt b/kmath-core/src/commonMain/kotlin/kscience/kmath/structures/BoxingNDField.kt
index ddec7bd25..dc65b12c4 100644
--- a/kmath-core/src/commonMain/kotlin/kscience/kmath/structures/BoxingNDField.kt
+++ b/kmath-core/src/commonMain/kotlin/kscience/kmath/structures/BoxingNDField.kt
@@ -15,8 +15,9 @@ public class BoxingNDField<T, F : Field<T>>(
     public fun buildBuffer(size: Int, initializer: (Int) -> T): Buffer<T> =
         bufferFactory(size, initializer)
 
-    public override fun check(vararg elements: NDBuffer<T>) {
-        check(elements.all { it.strides == strides }) { "Element strides are not the same as context strides" }
+    public override fun check(vararg elements: NDBuffer<T>): Array<out NDBuffer<T>> {
+        require(elements.all { it.strides == strides }) { "Element strides are not the same as context strides" }
+        return elements
     }
 
     public override fun produce(initializer: F.(IntArray) -> T): BufferedNDFieldElement<T, F> =
diff --git a/kmath-core/src/commonMain/kotlin/kscience/kmath/structures/BufferedNDAlgebra.kt b/kmath-core/src/commonMain/kotlin/kscience/kmath/structures/BufferedNDAlgebra.kt
index 66b4f19e1..251b1bcb5 100644
--- a/kmath-core/src/commonMain/kotlin/kscience/kmath/structures/BufferedNDAlgebra.kt
+++ b/kmath-core/src/commonMain/kotlin/kscience/kmath/structures/BufferedNDAlgebra.kt
@@ -5,8 +5,10 @@ import kscience.kmath.operations.*
 public interface BufferedNDAlgebra<T, C> : NDAlgebra<T, C, NDBuffer<T>> {
     public val strides: Strides
 
-    public override fun check(vararg elements: NDBuffer<T>): Unit =
+    public override fun check(vararg elements: NDBuffer<T>): Array<out NDBuffer<T>> {
         require(elements.all { it.strides == strides }) { ("Strides mismatch") }
+        return elements
+    }
 
     /**
      * Convert any [NDStructure] to buffered structure using strides from this context.
diff --git a/kmath-core/src/commonMain/kotlin/kscience/kmath/structures/NDAlgebra.kt b/kmath-core/src/commonMain/kotlin/kscience/kmath/structures/NDAlgebra.kt
index 35a65c487..4315f0423 100644
--- a/kmath-core/src/commonMain/kotlin/kscience/kmath/structures/NDAlgebra.kt
+++ b/kmath-core/src/commonMain/kotlin/kscience/kmath/structures/NDAlgebra.kt
@@ -11,7 +11,7 @@ import kscience.kmath.operations.Space
  * @property expected the expected shape.
  * @property actual the actual shape.
  */
-public class ShapeMismatchException(val expected: IntArray, val actual: IntArray) :
+public class ShapeMismatchException(public val expected: IntArray, public val actual: IntArray) :
     RuntimeException("Shape ${actual.contentToString()} doesn't fit in expected shape ${expected.contentToString()}.")
 
 /**
diff --git a/kmath-nd4j/README.md b/kmath-nd4j/README.md
index f8ca5eed2..fac24504a 100644
--- a/kmath-nd4j/README.md
+++ b/kmath-nd4j/README.md
@@ -13,26 +13,33 @@ This subproject implements the following features:
 >
 > ```gradle
 > repositories {
+>     mavenCentral()
 >     maven { url 'https://dl.bintray.com/mipt-npm/scientifik' }
 >     maven { url 'https://dl.bintray.com/mipt-npm/dev' }
 > }
 > 
 > dependencies {
 >     implementation 'scientifik:kmath-nd4j:0.1.4-dev-8'
+>     implementation 'org.nd4j:nd4j-native-platform:1.0.0-beta7'
 > }
 > ```
 > **Gradle Kotlin DSL:**
 >
 > ```kotlin
 > repositories {
+>     mavenCentral()
 >     maven("https://dl.bintray.com/mipt-npm/scientifik")
 >     maven("https://dl.bintray.com/mipt-npm/dev")
 > }
 > 
 > dependencies {
 >     implementation("scientifik:kmath-nd4j:0.1.4-dev-8")
+>     implementation("org.nd4j:nd4j-native-platform:1.0.0-beta7")
 > }
 > ```
+> 
+> This distribution also needs an implementation of ND4J API. The ND4J Native Platform is usually the fastest one, so 
+> it is included to the snippet.
 >
 
 ## Examples
diff --git a/kmath-nd4j/build.gradle.kts b/kmath-nd4j/build.gradle.kts
index 110a2ac30..67569b870 100644
--- a/kmath-nd4j/build.gradle.kts
+++ b/kmath-nd4j/build.gradle.kts
@@ -1,5 +1,5 @@
 plugins {
-    id("scientifik.jvm")
+    id("ru.mipt.npm.jvm")
 }
 
 dependencies {
diff --git a/kmath-nd4j/src/main/kotlin/kscience.kmath.nd4j/INDArrayAlgebra.kt b/kmath-nd4j/src/main/kotlin/kscience.kmath.nd4j/INDArrayAlgebra.kt
new file mode 100644
index 000000000..728ce3773
--- /dev/null
+++ b/kmath-nd4j/src/main/kotlin/kscience.kmath.nd4j/INDArrayAlgebra.kt
@@ -0,0 +1,284 @@
+package kscience.kmath.nd4j
+
+import org.nd4j.linalg.api.ndarray.INDArray
+import org.nd4j.linalg.factory.Nd4j
+import kscience.kmath.operations.*
+import kscience.kmath.structures.*
+
+/**
+ * Represents [NDAlgebra] over [INDArrayAlgebra].
+ *
+ * @param T the type of ND-structure element.
+ * @param C the type of the element context.
+ */
+public interface INDArrayAlgebra<T, C> : NDAlgebra<T, C, INDArrayStructure<T>> {
+    /**
+     * Wraps [INDArray] to [N].
+     */
+    public fun INDArray.wrap(): INDArrayStructure<T>
+
+    public override fun produce(initializer: C.(IntArray) -> T): INDArrayStructure<T> {
+        val struct = Nd4j.create(*shape)!!.wrap()
+        struct.indicesIterator().forEach { struct[it] = elementContext.initializer(it) }
+        return struct
+    }
+
+    public override fun map(arg: INDArrayStructure<T>, transform: C.(T) -> T): INDArrayStructure<T> {
+        check(arg)
+        val newStruct = arg.ndArray.dup().wrap()
+        newStruct.elements().forEach { (idx, value) -> newStruct[idx] = elementContext.transform(value) }
+        return newStruct
+    }
+
+    public override fun mapIndexed(
+        arg: INDArrayStructure<T>,
+        transform: C.(index: IntArray, T) -> T
+    ): INDArrayStructure<T> {
+        check(arg)
+        val new = Nd4j.create(*shape).wrap()
+        new.indicesIterator().forEach { idx -> new[idx] = elementContext.transform(idx, arg[idx]) }
+        return new
+    }
+
+    public override fun combine(
+        a: INDArrayStructure<T>,
+        b: INDArrayStructure<T>,
+        transform: C.(T, T) -> T
+    ): INDArrayStructure<T> {
+        check(a, b)
+        val new = Nd4j.create(*shape).wrap()
+        new.indicesIterator().forEach { idx -> new[idx] = elementContext.transform(a[idx], b[idx]) }
+        return new
+    }
+}
+
+/**
+ * Represents [NDSpace] over [INDArrayStructure].
+ *
+ * @param T the type of the element contained in ND structure.
+ * @param S the type of space of structure elements.
+ */
+public interface INDArraySpace<T, S> : NDSpace<T, S, INDArrayStructure<T>>, INDArrayAlgebra<T, S> where S : Space<T> {
+    public override val zero: INDArrayStructure<T>
+        get() = Nd4j.zeros(*shape).wrap()
+
+    public override fun add(a: INDArrayStructure<T>, b: INDArrayStructure<T>): INDArrayStructure<T> {
+        check(a, b)
+        return a.ndArray.add(b.ndArray).wrap()
+    }
+
+    public override operator fun INDArrayStructure<T>.minus(b: INDArrayStructure<T>): INDArrayStructure<T> {
+        check(this, b)
+        return ndArray.sub(b.ndArray).wrap()
+    }
+
+    public override operator fun INDArrayStructure<T>.unaryMinus(): INDArrayStructure<T> {
+        check(this)
+        return ndArray.neg().wrap()
+    }
+
+    public override fun multiply(a: INDArrayStructure<T>, k: Number): INDArrayStructure<T> {
+        check(a)
+        return a.ndArray.mul(k).wrap()
+    }
+
+    public override operator fun INDArrayStructure<T>.div(k: Number): INDArrayStructure<T> {
+        check(this)
+        return ndArray.div(k).wrap()
+    }
+
+    public override operator fun INDArrayStructure<T>.times(k: Number): INDArrayStructure<T> {
+        check(this)
+        return ndArray.mul(k).wrap()
+    }
+}
+
+/**
+ * Represents [NDRing] over [INDArrayStructure].
+ *
+ * @param T the type of the element contained in ND structure.
+ * @param R the type of ring of structure elements.
+ */
+public interface INDArrayRing<T, R> : NDRing<T, R, INDArrayStructure<T>>, INDArraySpace<T, R> where R : Ring<T> {
+    public override val one: INDArrayStructure<T>
+        get() = Nd4j.ones(*shape).wrap()
+
+    public override fun multiply(a: INDArrayStructure<T>, b: INDArrayStructure<T>): INDArrayStructure<T> {
+        check(a, b)
+        return a.ndArray.mul(b.ndArray).wrap()
+    }
+
+    public override operator fun INDArrayStructure<T>.minus(b: Number): INDArrayStructure<T> {
+        check(this)
+        return ndArray.sub(b).wrap()
+    }
+
+    public override operator fun INDArrayStructure<T>.plus(b: Number): INDArrayStructure<T> {
+        check(this)
+        return ndArray.add(b).wrap()
+    }
+
+    public override operator fun Number.minus(b: INDArrayStructure<T>): INDArrayStructure<T> {
+        check(b)
+        return b.ndArray.rsub(this).wrap()
+    }
+}
+
+/**
+ * Represents [NDField] over [INDArrayStructure].
+ *
+ * @param T the type of the element contained in ND structure.
+ * @param N the type of ND structure.
+ * @param F the type field of structure elements.
+ */
+public interface INDArrayField<T, F> : NDField<T, F, INDArrayStructure<T>>, INDArrayRing<T, F> where F : Field<T> {
+    public override fun divide(a: INDArrayStructure<T>, b: INDArrayStructure<T>): INDArrayStructure<T> {
+        check(a, b)
+        return a.ndArray.div(b.ndArray).wrap()
+    }
+
+    public override operator fun Number.div(b: INDArrayStructure<T>): INDArrayStructure<T> {
+        check(b)
+        return b.ndArray.rdiv(this).wrap()
+    }
+}
+
+/**
+ * Represents [NDField] over [INDArrayRealStructure].
+ */
+public class RealINDArrayField(public override val shape: IntArray) : INDArrayField<Double, RealField> {
+    public override val elementContext: RealField
+        get() = RealField
+
+    public override fun INDArray.wrap(): INDArrayStructure<Double> = check(asRealStructure())
+
+    public override operator fun INDArrayStructure<Double>.div(arg: Double): INDArrayStructure<Double> {
+        check(this)
+        return ndArray.div(arg).wrap()
+    }
+
+    public override operator fun INDArrayStructure<Double>.plus(arg: Double): INDArrayStructure<Double> {
+        check(this)
+        return ndArray.add(arg).wrap()
+    }
+
+    public override operator fun INDArrayStructure<Double>.minus(arg: Double): INDArrayStructure<Double> {
+        check(this)
+        return ndArray.sub(arg).wrap()
+    }
+
+    public override operator fun INDArrayStructure<Double>.times(arg: Double): INDArrayStructure<Double> {
+        check(this)
+        return ndArray.mul(arg).wrap()
+    }
+
+    public override operator fun Double.div(arg: INDArrayStructure<Double>): INDArrayStructure<Double> {
+        check(arg)
+        return arg.ndArray.rdiv(this).wrap()
+    }
+
+    public override operator fun Double.minus(arg: INDArrayStructure<Double>): INDArrayStructure<Double> {
+        check(arg)
+        return arg.ndArray.rsub(this).wrap()
+    }
+}
+
+/**
+ * Represents [NDField] over [INDArrayStructure] of [Float].
+ */
+public class FloatINDArrayField(public override val shape: IntArray) : INDArrayField<Float, FloatField> {
+    public override val elementContext: FloatField
+        get() = FloatField
+
+    public override fun INDArray.wrap(): INDArrayStructure<Float> = check(asFloatStructure())
+
+    public override operator fun INDArrayStructure<Float>.div(arg: Float): INDArrayStructure<Float> {
+        check(this)
+        return ndArray.div(arg).wrap()
+    }
+
+    public override operator fun INDArrayStructure<Float>.plus(arg: Float): INDArrayStructure<Float> {
+        check(this)
+        return ndArray.add(arg).wrap()
+    }
+
+    public override operator fun INDArrayStructure<Float>.minus(arg: Float): INDArrayStructure<Float> {
+        check(this)
+        return ndArray.sub(arg).wrap()
+    }
+
+    public override operator fun INDArrayStructure<Float>.times(arg: Float): INDArrayStructure<Float> {
+        check(this)
+        return ndArray.mul(arg).wrap()
+    }
+
+    public override operator fun Float.div(arg: INDArrayStructure<Float>): INDArrayStructure<Float> {
+        check(arg)
+        return arg.ndArray.rdiv(this).wrap()
+    }
+
+    public override operator fun Float.minus(arg: INDArrayStructure<Float>): INDArrayStructure<Float> {
+        check(arg)
+        return arg.ndArray.rsub(this).wrap()
+    }
+}
+
+/**
+ * Represents [NDRing] over [INDArrayIntStructure].
+ */
+public class IntINDArrayRing(public override val shape: IntArray) : INDArrayRing<Int, IntRing> {
+    public override val elementContext: IntRing
+        get() = IntRing
+
+    public override fun INDArray.wrap(): INDArrayStructure<Int> = check(asIntStructure())
+
+    public override operator fun INDArrayStructure<Int>.plus(arg: Int): INDArrayStructure<Int> {
+        check(this)
+        return ndArray.add(arg).wrap()
+    }
+
+    public override operator fun INDArrayStructure<Int>.minus(arg: Int): INDArrayStructure<Int> {
+        check(this)
+        return ndArray.sub(arg).wrap()
+    }
+
+    public override operator fun INDArrayStructure<Int>.times(arg: Int): INDArrayStructure<Int> {
+        check(this)
+        return ndArray.mul(arg).wrap()
+    }
+
+    public override operator fun Int.minus(arg: INDArrayStructure<Int>): INDArrayStructure<Int> {
+        check(arg)
+        return arg.ndArray.rsub(this).wrap()
+    }
+}
+
+/**
+ * Represents [NDRing] over [INDArrayStructure] of [Long].
+ */
+public class LongINDArrayRing(public override val shape: IntArray) : INDArrayRing<Long, LongRing> {
+    public override val elementContext: LongRing
+        get() = LongRing
+
+    public override fun INDArray.wrap(): INDArrayStructure<Long> = check(asLongStructure())
+
+    public override operator fun INDArrayStructure<Long>.plus(arg: Long): INDArrayStructure<Long> {
+        check(this)
+        return ndArray.add(arg).wrap()
+    }
+
+    public override operator fun INDArrayStructure<Long>.minus(arg: Long): INDArrayStructure<Long> {
+        check(this)
+        return ndArray.sub(arg).wrap()
+    }
+
+    public override operator fun INDArrayStructure<Long>.times(arg: Long): INDArrayStructure<Long> {
+        check(this)
+        return ndArray.mul(arg).wrap()
+    }
+
+    public override operator fun Long.minus(arg: INDArrayStructure<Long>): INDArrayStructure<Long> {
+        check(arg)
+        return arg.ndArray.rsub(this).wrap()
+    }
+}
diff --git a/kmath-nd4j/src/main/kotlin/scientifik.kmath.nd4j/INDArrayIterators.kt b/kmath-nd4j/src/main/kotlin/kscience.kmath.nd4j/INDArrayIterators.kt
similarity index 94%
rename from kmath-nd4j/src/main/kotlin/scientifik.kmath.nd4j/INDArrayIterators.kt
rename to kmath-nd4j/src/main/kotlin/kscience.kmath.nd4j/INDArrayIterators.kt
index 2759f9fdb..9e7ef9e16 100644
--- a/kmath-nd4j/src/main/kotlin/scientifik.kmath.nd4j/INDArrayIterators.kt
+++ b/kmath-nd4j/src/main/kotlin/kscience.kmath.nd4j/INDArrayIterators.kt
@@ -1,4 +1,4 @@
-package scientifik.kmath.nd4j
+package kscience.kmath.nd4j
 
 import org.nd4j.linalg.api.ndarray.INDArray
 import org.nd4j.linalg.api.shape.Shape
@@ -18,7 +18,7 @@ private class INDArrayIndicesIterator(private val iterateOver: INDArray) : Itera
     }
 }
 
-internal fun INDArray.indicesIterator(): Iterator<IntArray>     = INDArrayIndicesIterator(this)
+internal fun INDArray.indicesIterator(): Iterator<IntArray> = INDArrayIndicesIterator(this)
 
 private sealed class INDArrayIteratorBase<T>(protected val iterateOver: INDArray) : Iterator<Pair<IntArray, T>> {
     private var i: Int = 0
diff --git a/kmath-nd4j/src/main/kotlin/kscience.kmath.nd4j/INDArrayStructures.kt b/kmath-nd4j/src/main/kotlin/kscience.kmath.nd4j/INDArrayStructures.kt
new file mode 100644
index 000000000..5d4e1a979
--- /dev/null
+++ b/kmath-nd4j/src/main/kotlin/kscience.kmath.nd4j/INDArrayStructures.kt
@@ -0,0 +1,68 @@
+package kscience.kmath.nd4j
+
+import org.nd4j.linalg.api.ndarray.INDArray
+import kscience.kmath.structures.MutableNDStructure
+import kscience.kmath.structures.NDStructure
+
+/**
+ * Represents a [NDStructure] wrapping an [INDArray] object.
+ *
+ * @param T the type of items.
+ */
+public sealed class INDArrayStructure<T> : MutableNDStructure<T> {
+    /**
+     * The wrapped [INDArray].
+     */
+    public abstract val ndArray: INDArray
+
+    public override val shape: IntArray
+        get() = ndArray.shape().toIntArray()
+
+    internal abstract fun elementsIterator(): Iterator<Pair<IntArray, T>>
+    internal fun indicesIterator(): Iterator<IntArray> = ndArray.indicesIterator()
+    public override fun elements(): Sequence<Pair<IntArray, T>> = Sequence(::elementsIterator)
+}
+
+private data class INDArrayIntStructure(override val ndArray: INDArray) : INDArrayStructure<Int>() {
+    override fun elementsIterator(): Iterator<Pair<IntArray, Int>> = ndArray.intIterator()
+    override fun get(index: IntArray): Int = ndArray.getInt(*index)
+    override fun set(index: IntArray, value: Int): Unit = run { ndArray.putScalar(index, value) }
+}
+
+/**
+ * Wraps this [INDArray] to [INDArrayStructure].
+ */
+public fun INDArray.asIntStructure(): INDArrayStructure<Int> = INDArrayIntStructure(this)
+
+private data class INDArrayLongStructure(override val ndArray: INDArray) : INDArrayStructure<Long>() {
+    override fun elementsIterator(): Iterator<Pair<IntArray, Long>> = ndArray.longIterator()
+    override fun get(index: IntArray): Long = ndArray.getLong(*index.toLongArray())
+    override fun set(index: IntArray, value: Long): Unit = run { ndArray.putScalar(index, value.toDouble()) }
+}
+
+/**
+ * Wraps this [INDArray] to [INDArrayStructure].
+ */
+public fun INDArray.asLongStructure(): INDArrayStructure<Long> = INDArrayLongStructure(this)
+
+private data class INDArrayRealStructure(override val ndArray: INDArray) : INDArrayStructure<Double>() {
+    override fun elementsIterator(): Iterator<Pair<IntArray, Double>> = ndArray.realIterator()
+    override fun get(index: IntArray): Double = ndArray.getDouble(*index)
+    override fun set(index: IntArray, value: Double): Unit = run { ndArray.putScalar(index, value) }
+}
+
+/**
+ * Wraps this [INDArray] to [INDArrayStructure].
+ */
+public fun INDArray.asRealStructure(): INDArrayStructure<Double> = INDArrayRealStructure(this)
+
+private data class INDArrayFloatStructure(override val ndArray: INDArray) : INDArrayStructure<Float>() {
+    override fun elementsIterator(): Iterator<Pair<IntArray, Float>> = ndArray.floatIterator()
+    override fun get(index: IntArray): Float = ndArray.getFloat(*index)
+    override fun set(index: IntArray, value: Float): Unit = run { ndArray.putScalar(index, value) }
+}
+
+/**
+ * Wraps this [INDArray] to [INDArrayStructure].
+ */
+public fun INDArray.asFloatStructure(): INDArrayStructure<Float> = INDArrayFloatStructure(this)
diff --git a/kmath-nd4j/src/main/kotlin/scientifik.kmath.nd4j/arrays.kt b/kmath-nd4j/src/main/kotlin/kscience.kmath.nd4j/arrays.kt
similarity index 85%
rename from kmath-nd4j/src/main/kotlin/scientifik.kmath.nd4j/arrays.kt
rename to kmath-nd4j/src/main/kotlin/kscience.kmath.nd4j/arrays.kt
index 269fc89c2..798f81c35 100644
--- a/kmath-nd4j/src/main/kotlin/scientifik.kmath.nd4j/arrays.kt
+++ b/kmath-nd4j/src/main/kotlin/kscience.kmath.nd4j/arrays.kt
@@ -1,4 +1,4 @@
-package scientifik.kmath.nd4j
+package kscience.kmath.nd4j
 
 internal fun IntArray.toLongArray(): LongArray = LongArray(size) { this[it].toLong() }
 internal fun LongArray.toIntArray(): IntArray = IntArray(size) { this[it].toInt() }
diff --git a/kmath-nd4j/src/main/kotlin/scientifik.kmath.nd4j/INDArrayAlgebra.kt b/kmath-nd4j/src/main/kotlin/scientifik.kmath.nd4j/INDArrayAlgebra.kt
deleted file mode 100644
index c24e2ece6..000000000
--- a/kmath-nd4j/src/main/kotlin/scientifik.kmath.nd4j/INDArrayAlgebra.kt
+++ /dev/null
@@ -1,273 +0,0 @@
-package scientifik.kmath.nd4j
-
-import org.nd4j.linalg.api.ndarray.INDArray
-import org.nd4j.linalg.factory.Nd4j
-import scientifik.kmath.operations.*
-import scientifik.kmath.structures.*
-
-/**
- * Represents [NDAlgebra] over [INDArrayAlgebra].
- *
- * @param T the type of ND-structure element.
- * @param C the type of the element context.
- * @param N the type of the structure.
- */
-interface INDArrayAlgebra<T, C, N> : NDAlgebra<T, C, N> where N : INDArrayStructure<T>, N : MutableNDStructure<T> {
-    /**
-     * Wraps [INDArray] to [N].
-     */
-    fun INDArray.wrap(): N
-
-    override fun produce(initializer: C.(IntArray) -> T): N {
-        val struct = Nd4j.create(*shape)!!.wrap()
-        struct.indicesIterator().forEach { struct[it] = elementContext.initializer(it) }
-        return struct
-    }
-
-    override fun map(arg: N, transform: C.(T) -> T): N {
-        check(arg)
-        val newStruct = arg.ndArray.dup().wrap()
-        newStruct.elements().forEach { (idx, value) -> newStruct[idx] = elementContext.transform(value) }
-        return newStruct
-    }
-
-    override fun mapIndexed(arg: N, transform: C.(index: IntArray, T) -> T): N {
-        check(arg)
-        val new = Nd4j.create(*shape).wrap()
-        new.indicesIterator().forEach { idx -> new[idx] = elementContext.transform(idx, arg[idx]) }
-        return new
-    }
-
-    override fun combine(a: N, b: N, transform: C.(T, T) -> T): N {
-        check(a, b)
-        val new = Nd4j.create(*shape).wrap()
-        new.indicesIterator().forEach { idx -> new[idx] = elementContext.transform(a[idx], b[idx]) }
-        return new
-    }
-}
-
-/**
- * Represents [NDSpace] over [INDArrayStructure].
- *
- * @param T the type of the element contained in ND structure.
- * @param N the type of ND structure.
- * @param S the type of space of structure elements.
- */
-interface INDArraySpace<T, S, N> : NDSpace<T, S, N>, INDArrayAlgebra<T, S, N>
-        where S : Space<T>, N : INDArrayStructure<T>, N : MutableNDStructure<T> {
-
-    override val zero: N
-        get() = Nd4j.zeros(*shape).wrap()
-
-    override fun add(a: N, b: N): N {
-        check(a, b)
-        return a.ndArray.add(b.ndArray).wrap()
-    }
-
-    override operator fun N.minus(b: N): N {
-        check(this, b)
-        return ndArray.sub(b.ndArray).wrap()
-    }
-
-    override operator fun N.unaryMinus(): N {
-        check(this)
-        return ndArray.neg().wrap()
-    }
-
-    override fun multiply(a: N, k: Number): N {
-        check(a)
-        return a.ndArray.mul(k).wrap()
-    }
-
-    override operator fun N.div(k: Number): N {
-        check(this)
-        return ndArray.div(k).wrap()
-    }
-
-    override operator fun N.times(k: Number): N {
-        check(this)
-        return ndArray.mul(k).wrap()
-    }
-}
-
-/**
- * Represents [NDRing] over [INDArrayStructure].
- *
- * @param T the type of the element contained in ND structure.
- * @param N the type of ND structure.
- * @param R the type of ring of structure elements.
- */
-interface INDArrayRing<T, R, N> : NDRing<T, R, N>, INDArraySpace<T, R, N>
-        where R : Ring<T>, N : INDArrayStructure<T>, N : MutableNDStructure<T> {
-
-    override val one: N
-        get() = Nd4j.ones(*shape).wrap()
-
-    override fun multiply(a: N, b: N): N {
-        check(a, b)
-        return a.ndArray.mul(b.ndArray).wrap()
-    }
-
-    override operator fun N.minus(b: Number): N {
-        check(this)
-        return ndArray.sub(b).wrap()
-    }
-
-    override operator fun N.plus(b: Number): N {
-        check(this)
-        return ndArray.add(b).wrap()
-    }
-
-    override operator fun Number.minus(b: N): N {
-        check(b)
-        return b.ndArray.rsub(this).wrap()
-    }
-}
-
-/**
- * Represents [NDField] over [INDArrayStructure].
- *
- * @param T the type of the element contained in ND structure.
- * @param N the type of ND structure.
- * @param F the type field of structure elements.
- */
-interface INDArrayField<T, F, N> : NDField<T, F, N>, INDArrayRing<T, F, N>
-        where F : Field<T>, N : INDArrayStructure<T>, N : MutableNDStructure<T> {
-    override fun divide(a: N, b: N): N {
-        check(a, b)
-        return a.ndArray.div(b.ndArray).wrap()
-    }
-
-    override operator fun Number.div(b: N): N {
-        check(b)
-        return b.ndArray.rdiv(this).wrap()
-    }
-}
-
-/**
- * Represents [NDField] over [INDArrayRealStructure].
- */
-class RealINDArrayField(override val shape: IntArray, override val elementContext: Field<Double> = RealField) :
-    INDArrayField<Double, Field<Double>, INDArrayRealStructure> {
-    override fun INDArray.wrap(): INDArrayRealStructure = check(asRealStructure())
-    override operator fun INDArrayRealStructure.div(arg: Double): INDArrayRealStructure {
-        check(this)
-        return ndArray.div(arg).wrap()
-    }
-
-    override operator fun INDArrayRealStructure.plus(arg: Double): INDArrayRealStructure {
-        check(this)
-        return ndArray.add(arg).wrap()
-    }
-
-    override operator fun INDArrayRealStructure.minus(arg: Double): INDArrayRealStructure {
-        check(this)
-        return ndArray.sub(arg).wrap()
-    }
-
-    override operator fun INDArrayRealStructure.times(arg: Double): INDArrayRealStructure {
-        check(this)
-        return ndArray.mul(arg).wrap()
-    }
-
-    override operator fun Double.div(arg: INDArrayRealStructure): INDArrayRealStructure {
-        check(arg)
-        return arg.ndArray.rdiv(this).wrap()
-    }
-
-    override operator fun Double.minus(arg: INDArrayRealStructure): INDArrayRealStructure {
-        check(arg)
-        return arg.ndArray.rsub(this).wrap()
-    }
-}
-
-/**
- * Represents [NDField] over [INDArrayFloatStructure].
- */
-class FloatINDArrayField(override val shape: IntArray, override val elementContext: Field<Float> = FloatField) :
-    INDArrayField<Float, Field<Float>, INDArrayFloatStructure> {
-    override fun INDArray.wrap(): INDArrayFloatStructure = check(asFloatStructure())
-    override operator fun INDArrayFloatStructure.div(arg: Float): INDArrayFloatStructure {
-        check(this)
-        return ndArray.div(arg).wrap()
-    }
-
-    override operator fun INDArrayFloatStructure.plus(arg: Float): INDArrayFloatStructure {
-        check(this)
-        return ndArray.add(arg).wrap()
-    }
-
-    override operator fun INDArrayFloatStructure.minus(arg: Float): INDArrayFloatStructure {
-        check(this)
-        return ndArray.sub(arg).wrap()
-    }
-
-    override operator fun INDArrayFloatStructure.times(arg: Float): INDArrayFloatStructure {
-        check(this)
-        return ndArray.mul(arg).wrap()
-    }
-
-    override operator fun Float.div(arg: INDArrayFloatStructure): INDArrayFloatStructure {
-        check(arg)
-        return arg.ndArray.rdiv(this).wrap()
-    }
-
-    override operator fun Float.minus(arg: INDArrayFloatStructure): INDArrayFloatStructure {
-        check(arg)
-        return arg.ndArray.rsub(this).wrap()
-    }
-}
-
-/**
- * Represents [NDRing] over [INDArrayIntStructure].
- */
-class IntINDArrayRing(override val shape: IntArray, override val elementContext: Ring<Int> = IntRing) :
-    INDArrayRing<Int, Ring<Int>, INDArrayIntStructure> {
-    override fun INDArray.wrap(): INDArrayIntStructure = check(asIntStructure())
-    override operator fun INDArrayIntStructure.plus(arg: Int): INDArrayIntStructure {
-        check(this)
-        return ndArray.add(arg).wrap()
-    }
-
-    override operator fun INDArrayIntStructure.minus(arg: Int): INDArrayIntStructure {
-        check(this)
-        return ndArray.sub(arg).wrap()
-    }
-
-    override operator fun INDArrayIntStructure.times(arg: Int): INDArrayIntStructure {
-        check(this)
-        return ndArray.mul(arg).wrap()
-    }
-
-    override operator fun Int.minus(arg: INDArrayIntStructure): INDArrayIntStructure {
-        check(arg)
-        return arg.ndArray.rsub(this).wrap()
-    }
-}
-
-/**
- * Represents [NDRing] over [INDArrayLongStructure].
- */
-class LongINDArrayRing(override val shape: IntArray, override val elementContext: Ring<Long> = LongRing) :
-    INDArrayRing<Long, Ring<Long>, INDArrayLongStructure> {
-    override fun INDArray.wrap(): INDArrayLongStructure = check(asLongStructure())
-    override operator fun INDArrayLongStructure.plus(arg: Long): INDArrayLongStructure {
-        check(this)
-        return ndArray.add(arg).wrap()
-    }
-
-    override operator fun INDArrayLongStructure.minus(arg: Long): INDArrayLongStructure {
-        check(this)
-        return ndArray.sub(arg).wrap()
-    }
-
-    override operator fun INDArrayLongStructure.times(arg: Long): INDArrayLongStructure {
-        check(this)
-        return ndArray.mul(arg).wrap()
-    }
-
-    override operator fun Long.minus(arg: INDArrayLongStructure): INDArrayLongStructure {
-        check(arg)
-        return arg.ndArray.rsub(this).wrap()
-    }
-}
diff --git a/kmath-nd4j/src/main/kotlin/scientifik.kmath.nd4j/INDArrayStructures.kt b/kmath-nd4j/src/main/kotlin/scientifik.kmath.nd4j/INDArrayStructures.kt
deleted file mode 100644
index 39cefee3d..000000000
--- a/kmath-nd4j/src/main/kotlin/scientifik.kmath.nd4j/INDArrayStructures.kt
+++ /dev/null
@@ -1,80 +0,0 @@
-package scientifik.kmath.nd4j
-
-import org.nd4j.linalg.api.ndarray.INDArray
-import scientifik.kmath.structures.MutableNDStructure
-import scientifik.kmath.structures.NDStructure
-
-/**
- * Represents a [NDStructure] wrapping an [INDArray] object.
- *
- * @param T the type of items.
- */
-sealed class INDArrayStructure<T> : MutableNDStructure<T> {
-    /**
-     * The wrapped [INDArray].
-     */
-    abstract val ndArray: INDArray
-
-    override val shape: IntArray
-        get() = ndArray.shape().toIntArray()
-
-    internal abstract fun elementsIterator(): Iterator<Pair<IntArray, T>>
-    internal fun indicesIterator(): Iterator<IntArray> = ndArray.indicesIterator()
-    override fun elements(): Sequence<Pair<IntArray, T>> = Sequence(::elementsIterator)
-}
-
-/**
- * Represents a [NDStructure] over [INDArray] elements of which are accessed as ints.
- */
-data class INDArrayIntStructure(override val ndArray: INDArray) : INDArrayStructure<Int>() {
-    override fun elementsIterator(): Iterator<Pair<IntArray, Int>> = ndArray.intIterator()
-    override fun get(index: IntArray): Int = ndArray.getInt(*index)
-    override fun set(index: IntArray, value: Int): Unit = run { ndArray.putScalar(index, value) }
-}
-
-/**
- * Wraps this [INDArray] to [INDArrayIntStructure].
- */
-fun INDArray.asIntStructure(): INDArrayIntStructure = INDArrayIntStructure(this)
-
-/**
- * Represents a [NDStructure] over [INDArray] elements of which are accessed as longs.
- */
-data class INDArrayLongStructure(override val ndArray: INDArray) : INDArrayStructure<Long>() {
-    override fun elementsIterator(): Iterator<Pair<IntArray, Long>> = ndArray.longIterator()
-    override fun get(index: IntArray): Long = ndArray.getLong(*index.toLongArray())
-    override fun set(index: IntArray, value: Long): Unit = run { ndArray.putScalar(index, value.toDouble()) }
-}
-
-/**
- * Wraps this [INDArray] to [INDArrayLongStructure].
- */
-fun INDArray.asLongStructure(): INDArrayLongStructure = INDArrayLongStructure(this)
-
-/**
- * Represents a [NDStructure] over [INDArray] elements of which are accessed as reals.
- */
-data class INDArrayRealStructure(override val ndArray: INDArray) : INDArrayStructure<Double>() {
-    override fun elementsIterator(): Iterator<Pair<IntArray, Double>> = ndArray.realIterator()
-    override fun get(index: IntArray): Double = ndArray.getDouble(*index)
-    override fun set(index: IntArray, value: Double): Unit = run { ndArray.putScalar(index, value) }
-}
-
-/**
- * Wraps this [INDArray] to [INDArrayRealStructure].
- */
-fun INDArray.asRealStructure(): INDArrayRealStructure = INDArrayRealStructure(this)
-
-/**
- * Represents a [NDStructure] over [INDArray] elements of which are accessed as floats.
- */
-data class INDArrayFloatStructure(override val ndArray: INDArray) : INDArrayStructure<Float>() {
-    override fun elementsIterator(): Iterator<Pair<IntArray, Float>> = ndArray.floatIterator()
-    override fun get(index: IntArray): Float = ndArray.getFloat(*index)
-    override fun set(index: IntArray, value: Float): Unit = run { ndArray.putScalar(index, value) }
-}
-
-/**
- * Wraps this [INDArray] to [INDArrayFloatStructure].
- */
-fun INDArray.asFloatStructure(): INDArrayFloatStructure = INDArrayFloatStructure(this)
diff --git a/kmath-nd4j/src/test/kotlin/scientifik/kmath/nd4j/INDArrayAlgebraTest.kt b/kmath-nd4j/src/test/kotlin/kscience/kmath/nd4j/INDArrayAlgebraTest.kt
similarity index 78%
rename from kmath-nd4j/src/test/kotlin/scientifik/kmath/nd4j/INDArrayAlgebraTest.kt
rename to kmath-nd4j/src/test/kotlin/kscience/kmath/nd4j/INDArrayAlgebraTest.kt
index 4aa40c233..1a4f4c9f3 100644
--- a/kmath-nd4j/src/test/kotlin/scientifik/kmath/nd4j/INDArrayAlgebraTest.kt
+++ b/kmath-nd4j/src/test/kotlin/kscience/kmath/nd4j/INDArrayAlgebraTest.kt
@@ -1,15 +1,16 @@
-package scientifik.kmath.nd4j
+package kscience.kmath.nd4j
 
 import org.nd4j.linalg.factory.Nd4j
-import scientifik.kmath.operations.invoke
+import kscience.kmath.operations.invoke
 import kotlin.test.Test
 import kotlin.test.assertEquals
+import kotlin.test.fail
 
 internal class INDArrayAlgebraTest {
     @Test
     fun testProduce() {
         val res = (RealINDArrayField(intArrayOf(2, 2))) { produce { it.sum().toDouble() } }
-        val expected = Nd4j.create(2, 2)!!.asRealStructure()
+        val expected = (Nd4j.create(2, 2) ?: fail()).asRealStructure()
         expected[intArrayOf(0, 0)] = 0.0
         expected[intArrayOf(0, 1)] = 1.0
         expected[intArrayOf(1, 0)] = 1.0
@@ -20,7 +21,7 @@ internal class INDArrayAlgebraTest {
     @Test
     fun testMap() {
         val res = (IntINDArrayRing(intArrayOf(2, 2))) { map(one) { it + it * 2 } }
-        val expected = Nd4j.create(2, 2)!!.asIntStructure()
+        val expected = (Nd4j.create(2, 2) ?: fail()).asIntStructure()
         expected[intArrayOf(0, 0)] = 3
         expected[intArrayOf(0, 1)] = 3
         expected[intArrayOf(1, 0)] = 3
@@ -31,7 +32,7 @@ internal class INDArrayAlgebraTest {
     @Test
     fun testAdd() {
         val res = (IntINDArrayRing(intArrayOf(2, 2))) { one + 25 }
-        val expected = Nd4j.create(2, 2)!!.asIntStructure()
+        val expected = (Nd4j.create(2, 2) ?: fail()).asIntStructure()
         expected[intArrayOf(0, 0)] = 26
         expected[intArrayOf(0, 1)] = 26
         expected[intArrayOf(1, 0)] = 26
diff --git a/kmath-nd4j/src/test/kotlin/scientifik/kmath/nd4j/INDArrayStructureTest.kt b/kmath-nd4j/src/test/kotlin/kscience/kmath/nd4j/INDArrayStructureTest.kt
similarity index 55%
rename from kmath-nd4j/src/test/kotlin/scientifik/kmath/nd4j/INDArrayStructureTest.kt
rename to kmath-nd4j/src/test/kotlin/kscience/kmath/nd4j/INDArrayStructureTest.kt
index dfede6d32..63426d7f9 100644
--- a/kmath-nd4j/src/test/kotlin/scientifik/kmath/nd4j/INDArrayStructureTest.kt
+++ b/kmath-nd4j/src/test/kotlin/kscience/kmath/nd4j/INDArrayStructureTest.kt
@@ -1,70 +1,71 @@
-package scientifik.kmath.nd4j
+package kscience.kmath.nd4j
 
+import kscience.kmath.structures.get
 import org.nd4j.linalg.factory.Nd4j
-import scientifik.kmath.structures.get
 import kotlin.test.Test
 import kotlin.test.assertEquals
 import kotlin.test.assertNotEquals
+import kotlin.test.fail
 
 internal class INDArrayStructureTest {
     @Test
     fun testElements() {
         val nd = Nd4j.create(doubleArrayOf(1.0, 2.0, 3.0))!!
-        val struct = INDArrayRealStructure(nd)
+        val struct = nd.asRealStructure()
         val res = struct.elements().map(Pair<IntArray, Double>::second).toList()
         assertEquals(listOf(1.0, 2.0, 3.0), res)
     }
 
     @Test
     fun testShape() {
-        val nd = Nd4j.rand(10, 2, 3, 6)!!
-        val struct = INDArrayLongStructure(nd)
+        val nd = Nd4j.rand(10, 2, 3, 6) ?: fail()
+        val struct = nd.asRealStructure()
         assertEquals(intArrayOf(10, 2, 3, 6).toList(), struct.shape.toList())
     }
 
     @Test
     fun testEquals() {
-        val nd1 = Nd4j.create(doubleArrayOf(1.0, 2.0, 3.0))!!
-        val struct1 = INDArrayRealStructure(nd1)
+        val nd1 = Nd4j.create(doubleArrayOf(1.0, 2.0, 3.0)) ?: fail()
+        val struct1 = nd1.asRealStructure()
         assertEquals(struct1, struct1)
-        assertNotEquals(struct1, null as INDArrayRealStructure?)
-        val nd2 = Nd4j.create(doubleArrayOf(1.0, 2.0, 3.0))!!
-        val struct2 = INDArrayRealStructure(nd2)
+        assertNotEquals(struct1 as Any?, null)
+        val nd2 = Nd4j.create(doubleArrayOf(1.0, 2.0, 3.0)) ?: fail()
+        val struct2 = nd2.asRealStructure()
         assertEquals(struct1, struct2)
         assertEquals(struct2, struct1)
-        val nd3 = Nd4j.create(doubleArrayOf(1.0, 2.0, 3.0))!!
-        val struct3 = INDArrayRealStructure(nd3)
+        val nd3 = Nd4j.create(doubleArrayOf(1.0, 2.0, 3.0)) ?: fail()
+        val struct3 = nd3.asRealStructure()
         assertEquals(struct2, struct3)
         assertEquals(struct1, struct3)
     }
 
     @Test
     fun testHashCode() {
-        val nd1 = Nd4j.create(doubleArrayOf(1.0, 2.0, 3.0))!!
-        val struct1 = INDArrayRealStructure(nd1)
-        val nd2 = Nd4j.create(doubleArrayOf(1.0, 2.0, 3.0))!!
-        val struct2 = INDArrayRealStructure(nd2)
+        val nd1 = Nd4j.create(doubleArrayOf(1.0, 2.0, 3.0))?:fail()
+        val struct1 = nd1.asRealStructure()
+        val nd2 = Nd4j.create(doubleArrayOf(1.0, 2.0, 3.0))?:fail()
+        val struct2 = nd2.asRealStructure()
         assertEquals(struct1.hashCode(), struct2.hashCode())
     }
 
     @Test
     fun testDimension() {
         val nd = Nd4j.rand(8, 16, 3, 7, 1)!!
-        val struct = INDArrayFloatStructure(nd)
+        val struct = nd.asFloatStructure()
         assertEquals(5, struct.dimension)
     }
 
     @Test
     fun testGet() {
-        val nd = Nd4j.rand(10, 2, 3, 6)!!
-        val struct = INDArrayIntStructure(nd)
+        val nd = Nd4j.rand(10, 2, 3, 6)?:fail()
+        val struct = nd.asIntStructure()
         assertEquals(nd.getInt(0, 0, 0, 0), struct[0, 0, 0, 0])
     }
 
     @Test
     fun testSet() {
         val nd = Nd4j.rand(17, 12, 4, 8)!!
-        val struct = INDArrayIntStructure(nd)
+        val struct = nd.asLongStructure()
         struct[intArrayOf(1, 2, 3, 4)] = 777
         assertEquals(777, struct[1, 2, 3, 4])
     }