BAEL-1215: Introduction to the Suanshu math library (#5469)

* BAEL-1215: Introduction to the Suanshu math library

* Updated examples based on feedback.

libraries/pom.xml

@@ -711,6 +711,12 @@
             <version>${snakeyaml.version}</version>            
         </dependency>       
 
+        <dependency>
+            <groupId>com.numericalmethod</groupId>
+            <artifactId>suanshu</artifactId>
+            <version>${suanshu.version}</version>
+        </dependency>
+
     </dependencies>
 
     <repositories>
@@ -731,6 +737,12 @@
             <id>Apache Staging</id>
             <url>https://repository.apache.org/content/groups/staging</url>
         </repository>
+        <repository>
+            <id>nm-repo</id>
+            <name>Numerical Method's Maven Repository</name>
+            <url>http://repo.numericalmethod.com/maven/</url>
+            <layout>default</layout>
+        </repository>
     </repositories>
 
 
@@ -835,6 +847,7 @@
     </build>
 
     <properties>
+        <suanshu.version>4.0.0</suanshu.version>
         <snakeyaml.version>1.21</snakeyaml.version>
         <googleclient.version>1.23.0</googleclient.version>
         <crdt.version>0.1.0</crdt.version>

libraries/src/main/java/com/baeldung/suanshu/SuanShuMath.java

@@ -0,0 +1,142 @@
+package com.baeldung.suanshu;
+
+import java.util.List;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import com.numericalmethod.suanshu.algebra.linear.matrix.doubles.Matrix;
+import com.numericalmethod.suanshu.algebra.linear.vector.doubles.Vector;
+import com.numericalmethod.suanshu.algebra.linear.vector.doubles.dense.DenseVector;
+import com.numericalmethod.suanshu.algebra.linear.matrix.doubles.matrixtype.dense.DenseMatrix;
+import com.numericalmethod.suanshu.algebra.linear.matrix.doubles.operation.Inverse;
+import com.numericalmethod.suanshu.analysis.function.polynomial.Polynomial;
+import com.numericalmethod.suanshu.analysis.function.polynomial.root.PolyRoot;
+import com.numericalmethod.suanshu.analysis.function.polynomial.root.PolyRootSolver;
+import com.numericalmethod.suanshu.number.complex.Complex;
+
+class SuanShuMath {
+
+    private static final Logger log = LoggerFactory.getLogger(SuanShuMath.class);
+
+    public static void main(String[] args) throws Exception {
+        SuanShuMath math = new SuanShuMath();
+
+        math.addingVectors();
+        math.scaleVector();
+        math.innerProductVectors();
+        math.addingIncorrectVectors();
+
+        math.addingMatrices();
+        math.multiplyMatrices();
+        math.multiplyIncorrectMatrices();
+        math.inverseMatrix();
+
+        Polynomial p = math.createPolynomial();
+        math.evaluatePolynomial(p);
+        math.solvePolynomial();
+    }
+
+    public void addingVectors() throws Exception {
+        Vector v1 = new DenseVector(new double[]{1, 2, 3, 4, 5});
+        Vector v2 = new DenseVector(new double[]{5, 4, 3, 2, 1});
+        Vector v3 = v1.add(v2);
+        log.info("Adding vectors: {}", v3);
+    }
+
+    public void scaleVector() throws Exception {
+        Vector v1 = new DenseVector(new double[]{1, 2, 3, 4, 5});
+        Vector v2 = v1.scaled(2.0);
+        log.info("Scaling a vector: {}", v2);
+    }
+
+    public void innerProductVectors() throws Exception {
+        Vector v1 = new DenseVector(new double[]{1, 2, 3, 4, 5});
+        Vector v2 = new DenseVector(new double[]{5, 4, 3, 2, 1});
+        double inner = v1.innerProduct(v2);
+        log.info("Vector inner product: {}", inner);
+    }
+
+    public void addingIncorrectVectors() throws Exception {
+        Vector v1 = new DenseVector(new double[]{1, 2, 3});
+        Vector v2 = new DenseVector(new double[]{5, 4});
+        Vector v3 = v1.add(v2);
+        log.info("Adding vectors: {}", v3);
+    }
+
+    public void addingMatrices() throws Exception {
+        Matrix m1 = new DenseMatrix(new double[][]{
+            {1, 2, 3},
+            {4, 5, 6}
+        });
+
+        Matrix m2 = new DenseMatrix(new double[][]{
+            {3, 2, 1},
+            {6, 5, 4}
+        });
+
+        Matrix m3 = m1.add(m2);
+        log.info("Adding matrices: {}", m3);
+    }
+
+    public void multiplyMatrices() throws Exception {
+        Matrix m1 = new DenseMatrix(new double[][]{
+            {1, 2, 3},
+            {4, 5, 6}
+        });
+
+        Matrix m2 = new DenseMatrix(new double[][]{
+            {1, 4},
+            {2, 5},
+            {3, 6}
+        });
+
+        Matrix m3 = m1.multiply(m2);
+        log.info("Multiplying matrices: {}", m3);
+    }
+
+    public void multiplyIncorrectMatrices() throws Exception {
+        Matrix m1 = new DenseMatrix(new double[][]{
+            {1, 2, 3},
+            {4, 5, 6}
+        });
+
+        Matrix m2 = new DenseMatrix(new double[][]{
+            {3, 2, 1},
+            {6, 5, 4}
+        });
+
+        Matrix m3 = m1.multiply(m2);
+        log.info("Multiplying matrices: {}", m3);
+    }
+
+    public void inverseMatrix() {
+        Matrix m1 = new DenseMatrix(new double[][]{
+            {1, 2},
+            {3, 4}
+        });
+
+        Inverse m2 = new Inverse(m1);
+        log.info("Inverting a matrix: {}", m2);
+        log.info("Verifying a matrix inverse: {}", m1.multiply(m2));
+    }
+
+    public Polynomial createPolynomial() {
+        return new Polynomial(new double[]{3, -5, 1});
+    }
+
+    public void evaluatePolynomial(Polynomial p) {
+        // Evaluate using a real number
+        log.info("Evaluating a polynomial using a real number: {}", p.evaluate(5));
+        // Evaluate using a complex number
+        log.info("Evaluating a polynomial using a complex number: {}", p.evaluate(new Complex(1, 2)));
+    }
+
+    public void solvePolynomial() {
+        Polynomial p = new Polynomial(new double[]{2, 2, -4});
+        PolyRootSolver solver = new PolyRoot();
+        List<? extends Number> roots = solver.solve(p);
+        log.info("Finding polynomial roots: {}", roots);
+    }
+
+}