diff --git a/kmath-noa/src/main/kotlin/space/kscience/kmath/noa/algebras.kt b/kmath-noa/src/main/kotlin/space/kscience/kmath/noa/algebras.kt
index baf4b99f9..94a2a0192 100644
--- a/kmath-noa/src/main/kotlin/space/kscience/kmath/noa/algebras.kt
+++ b/kmath-noa/src/main/kotlin/space/kscience/kmath/noa/algebras.kt
@@ -36,14 +36,14 @@ protected constructor(protected val scope: NoaScope) :
 
     override fun Tensor<T>.value(): T = tensor.item()
 
-    public abstract fun randDiscrete(low: Long, high: Long, shape: IntArray, device: Device): TensorType
+    public abstract fun randDiscrete(low: Long, high: Long, shape: IntArray, device: Device = Device.CPU): TensorType
 
     @PerformancePitfall
     public abstract fun Tensor<T>.copyToArray(): PrimitiveArray
 
-    public abstract fun copyFromArray(array: PrimitiveArray, shape: IntArray, device: Device): TensorType
+    public abstract fun copyFromArray(array: PrimitiveArray, shape: IntArray, device: Device = Device.CPU): TensorType
 
-    public abstract fun full(value: T, shape: IntArray, device: Device): TensorType
+    public abstract fun full(value: T, shape: IntArray, device: Device = Device.CPU): TensorType
 
     override operator fun Tensor<T>.times(other: Tensor<T>): TensorType {
         return wrap(JNoa.timesTensor(tensor.tensorHandle, other.tensor.tensorHandle))
@@ -136,10 +136,10 @@ protected constructor(protected val scope: NoaScope) :
     public fun Tensor<T>.copy(): TensorType =
         wrap(JNoa.copyTensor(tensor.tensorHandle))
 
-    public fun Tensor<T>.copyToDevice(device: Device): TensorType =
+    public fun Tensor<T>.copyToDevice(device: Device = Device.CPU): TensorType =
         wrap(JNoa.copyToDevice(tensor.tensorHandle, device.toInt()))
 
-    public abstract fun loadJitModule(path: String, device: Device): NoaJitModule
+    public abstract fun loadJitModule(path: String, device: Device = Device.CPU): NoaJitModule
 
     public fun NoaJitModule.forward(parameters: Tensor<T>): TensorType =
         wrap(JNoa.forwardPass(jitModuleHandle, parameters.tensor.tensorHandle))
@@ -193,9 +193,9 @@ protected constructor(scope: NoaScope) :
     override fun Tensor<T>.variance(dim: Int, keepDim: Boolean): TensorType =
         wrap(JNoa.varDimTensor(tensor.tensorHandle, dim, keepDim))
 
-    public abstract fun randNormal(shape: IntArray, device: Device): TensorType
+    public abstract fun randNormal(shape: IntArray, device: Device = Device.CPU): TensorType
 
-    public abstract fun randUniform(shape: IntArray, device: Device): TensorType
+    public abstract fun randUniform(shape: IntArray, device: Device = Device.CPU): TensorType
 
     public fun Tensor<T>.randUniform(): TensorType =
         wrap(JNoa.randLike(tensor.tensorHandle))
@@ -301,7 +301,7 @@ protected constructor(scope: NoaScope) :
         return Pair(wrap(S), wrap(V))
     }
 
-    public fun TensorType.autoGradient(variable: TensorType, retainGraph: Boolean): TensorType =
+    public fun TensorType.autoGradient(variable: TensorType, retainGraph: Boolean = false): TensorType =
         wrap(JNoa.autoGradTensor(tensorHandle, variable.tensorHandle, retainGraph))
 
     public fun TensorType.autoHessian(variable: TensorType): TensorType =
diff --git a/kmath-noa/src/test/kotlin/space/kscience/kmath/noa/TestTensor.kt b/kmath-noa/src/test/kotlin/space/kscience/kmath/noa/TestTensor.kt
new file mode 100644
index 000000000..a02c2a5fb
--- /dev/null
+++ b/kmath-noa/src/test/kotlin/space/kscience/kmath/noa/TestTensor.kt
@@ -0,0 +1,40 @@
+/*
+ * Copyright 2018-2021 KMath contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package space.kscience.kmath.noa
+
+import kotlin.test.Test
+import kotlin.test.assertEquals
+import kotlin.test.assertTrue
+
+
+internal fun NoaFloat.testingCopying(device: Device = Device.CPU): Unit {
+    val array = (1..24).map { 10f * it * it }.toFloatArray()
+    val shape = intArrayOf(2, 3, 4)
+    val tensor = copyFromArray(array, shape = shape, device = device)
+    val copyOfTensor = tensor.copy()
+    tensor[intArrayOf(1, 2, 3)] = 0.1f
+    assertTrue(copyOfTensor.copyToArray() contentEquals array)
+    assertEquals(0.1f, tensor[intArrayOf(1, 2, 3)])
+    if(device != Device.CPU){
+        val normalCpu = randNormal(intArrayOf(2, 3))
+        val normalGpu = normalCpu.copyToDevice(device)
+        assertTrue(normalCpu.copyToArray() contentEquals normalGpu.copyToArray())
+
+        val uniformGpu = randUniform(intArrayOf(3,2),device)
+        val uniformCpu = uniformGpu.copyToDevice(Device.CPU)
+        assertTrue(uniformGpu.copyToArray() contentEquals uniformCpu.copyToArray())
+    }
+}
+
+
+class TestTensor {
+    @Test
+    fun testCopying(): Unit = NoaFloat {
+        withCuda { device ->
+            testingCopying(device)
+        }
+    }!!
+}
\ No newline at end of file
diff --git a/kmath-noa/src/test/kotlin/space/kscience/kmath/noa/TestUtils.kt b/kmath-noa/src/test/kotlin/space/kscience/kmath/noa/TestUtils.kt
index 21fe71f9c..ac82b9425 100644
--- a/kmath-noa/src/test/kotlin/space/kscience/kmath/noa/TestUtils.kt
+++ b/kmath-noa/src/test/kotlin/space/kscience/kmath/noa/TestUtils.kt
@@ -46,7 +46,7 @@ class TestUtils {
     }
 
     @Test
-    fun testSetNumThreads(){
+    fun testSetNumThreads() {
         val numThreads = 2
         setNumThreads(numThreads)
         assertEquals(numThreads, getNumThreads())
@@ -59,6 +59,4 @@ class TestUtils {
         }
     }!!
 
-
-    
 }