[BAEL-2996] Added ND4J dependency and matrices multiplication test

libraries-2/pom.xml

@@ -54,6 +54,11 @@
             <groupId>org.ejml</groupId>
             <artifactId>ejml-all</artifactId>
             <version>${ejml.version}</version>
+        </dependency>
+		<dependency>
+			<groupId>org.nd4j</groupId>
+			<artifactId>nd4j-native</artifactId>
+			<version>${nd4j.version}</version>
 		</dependency>
 		<dependency>
 			<groupId>colt</groupId>
@@ -124,7 +129,8 @@
 		<chronicle.map.version>3.17.2</chronicle.map.version>
         <crawler4j.version>4.4.0</crawler4j.version>
 		<spring-boot-starter.version>2.1.4.RELEASE</spring-boot-starter.version>
-		<ejml.version>0.37.1</ejml.version>
+		<ejml.version>0.38</ejml.version>
+		<nd4j.version>1.0.0-beta4</nd4j.version>
 		<colt.version>1.2.0</colt.version>
 		<la4j.version>0.6.0</la4j.version>
 	</properties>

libraries-2/src/test/java/com/baeldung/nd4j/INDArrayUnitTest.java

@@ -0,0 +1,40 @@
+package com.baeldung.nd4j;
+
+import org.junit.jupiter.api.Test;
+import org.nd4j.linalg.api.ndarray.INDArray;
+import org.nd4j.linalg.factory.Nd4j;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class INDArrayUnitTest {
+
+    @Test
+    void givenTwoMatrices_whenMultiply_thenMultiplicatedMatrix() {
+        INDArray firstMatrix = Nd4j.create(
+          new double[][]{
+            new double[]{1d, 5d},
+            new double[]{2d, 3d},
+            new double[]{1d, 7d}
+          }
+        );
+
+        INDArray secondMatrix = Nd4j.create(
+          new double[][] {
+            new double[] {1d, 2d, 3d, 7d},
+            new double[] {5d, 2d, 8d, 1d}
+          }
+        );
+
+        INDArray expected = Nd4j.create(
+          new double[][] {
+            new double[] {26d, 12d, 43d, 12d},
+            new double[] {17d, 10d, 30d, 17d},
+            new double[] {36d, 16d, 59d, 14d}
+          }
+        );
+
+        INDArray actual = firstMatrix.mmul(secondMatrix);
+
+        assertThat(actual).isEqualTo(expected);
+    }
+}