diff --git a/libraries-apache-commons/src/main/java/com/baeldung/commons/math3/MatrixMultiplication.java b/libraries-apache-commons/src/main/java/com/baeldung/commons/math3/MatrixMultiplication.java new file mode 100644 index 0000000000..12252d8d14 --- /dev/null +++ b/libraries-apache-commons/src/main/java/com/baeldung/commons/math3/MatrixMultiplication.java @@ -0,0 +1,6 @@ +package com.baeldung.commons.math3; + +public class MatrixMultiplication { + + +} diff --git a/libraries-apache-commons/src/test/java/com/baeldung/commons/math/RealMatrixUnitTest.java b/libraries-apache-commons/src/test/java/com/baeldung/commons/math/RealMatrixUnitTest.java new file mode 100644 index 0000000000..fca2bf6dd1 --- /dev/null +++ b/libraries-apache-commons/src/test/java/com/baeldung/commons/math/RealMatrixUnitTest.java @@ -0,0 +1,41 @@ +package com.baeldung.commons.math; + +import org.apache.commons.math3.linear.Array2DRowRealMatrix; +import org.apache.commons.math3.linear.RealMatrix; +import org.junit.jupiter.api.Test; + +import static org.assertj.core.api.Assertions.assertThat; + +class RealMatrixUnitTest { + + @Test + void givenTwoMatrices_whenMultiply_thenMultiplicatedMatrix() { + RealMatrix firstMatrix = new Array2DRowRealMatrix( + new double[][] { + new double[] {1d, 5d}, + new double[] {2d, 3d}, + new double[] {1d ,7d} + } + ); + + RealMatrix secondMatrix = new Array2DRowRealMatrix( + new double[][] { + new double[] {1d, 2d, 3d, 7d}, + new double[] {5d, 2d, 8d, 1d} + } + ); + + RealMatrix expected = new Array2DRowRealMatrix( + new double[][] { + new double[] {26d, 12d, 43d, 12d}, + new double[] {17d, 10d, 30d, 17d}, + new double[] {36d, 16d, 59d, 14d} + } + ); + + RealMatrix actual = firstMatrix.multiply(secondMatrix); + + assertThat(actual).isEqualTo(expected); + } + +}