init test for analytic algebra

kmath-core/src/commonTest/kotlin/space/kscience/kmath/tensors/core/TestDoubleAnalyticTensorAlgebra.kt

@@ -0,0 +1,35 @@
+package space.kscience.kmath.tensors.core
+
+import kotlin.math.abs
+import kotlin.math.exp
+import kotlin.test.Test
+import kotlin.test.assertEquals
+import kotlin.test.assertTrue
+
+class TestDoubleAnalyticTensorAlgebra {
+
+    val shape = intArrayOf(2, 1, 3, 2)
+    val buffer = doubleArrayOf(27.1, 20.0, 19.84, 23.123, 0.0, 1.0, 3.23, 133.7, 25.3, 100.3, 11.0, 12.012)
+    val tensor = DoubleTensor(shape, buffer)
+
+    fun DoubleArray.fmap(transform: (Double) -> Double): DoubleArray {
+        return this.map(transform).toDoubleArray()
+    }
+
+    fun DoubleArray.deltaEqual(other: DoubleArray, delta: Double = 1e-5): Boolean {
+        for ((elem1, elem2) in this.asSequence().zip(other.asSequence())) {
+            if (abs(elem1 - elem2) > delta) {
+                return false
+            }
+        }
+        return true
+    }
+
+    @Test
+    fun testExp() = DoubleAnalyticTensorAlgebra {
+        tensor.exp().let {
+            assertTrue { shape contentEquals it.shape }
+            assertTrue { buffer.fmap(::exp).deltaEqual(it.buffer.array())}
+        }
+    }
+}

kmath-core/src/commonTest/kotlin/space/kscience/kmath/tensors/core/TestDoubleTensorAlgebra.kt

@@ -79,4 +79,8 @@ class TestDoubleTensorAlgebra {
         assertTrue(expected.buffer.array() contentEquals assignResult.buffer.array())
     }
 
+    @Test
+    fun testContentEqual() = DoubleTensorAlgebra {
+        //TODO()
+    }
 }