Matrix Multiplication Write a method called multiply in the Matrix class that takes an instance of Matrix as a parameter and returns the result of matrix multiplication. Complete the definition of the class Matrix and method definition multiply shown here and in the starter code. public class Matrix { public Matrix multiply(Matrix other) { // fill in code here } } For purposes of this exercise, you should assume (without checking) that the matrices to be multiplied have the correct shapes, ie, that this.numCols() is equivalent to other.numRows(). To multiply matrices, the number of columns in the first matrix must equal the number of rows in the second matrix. In general, if we multiply an m x n matrix A (ie, having m rows and n columns) by a n x p matrix B (ie, having n rows and p columns), the product will have size m x p (ie, m rows and p columns). Here is a simple illustration of the computation for two 2 x 2 matrices: Examples Example 1 If A and B were both instances of the Matrix class with the following data, respectively, 0.0 1.0 2.0 2.0 1.0 2.0 2.0 2.0 2.0 2.0 0.0 2.0 the product a.multiply(b) would be the Matrix containing the following data: 2.0 6.0 6.0 10.0 Example 2 If A and B were both instances of the Matrix class with the following data, respectively, 1.0 3.0 1.0 2.0 3.0 1.0 0.0 3.0 1.0 0.0 3.0 1.0 1.0 1.0 2.0 3.0 2.0 3.0 0.0 1.0 the product a.multiply(b) would be the Matrix containing the following data: 9.0 15.0 5.0 9.0 7.0 11.0 Matrix.java code is attached import java.util.Random; public class Matrix { // Largest random value in Matrix will be MAX_VALUE-1 privatestaticfinalintMAX_VALUE = 3; privatedouble[][] matrix; // Constructor initializes an empty matrix publicMatrix(intnumRows, intnumCols) { matrix = newdouble[numRows][numCols]; } // Fill Matrix with random small integers for testing publicvoidfillMatrix() { Randomrand = newRandom(); for (intr = 0; r < numRows(); r++) { for (intc = 0; c < numCols(); c++) { matrix[r][c] = rand.nextInt(MAX_VALUE); } } } // Return number of rows in Matrix object publicintnumRows() { returnmatrix.length; } // Return number of columns in Matrix object publicintnumCols() { return (matrix.length == 0) ?0:matrix[0].length; } // Return String representation of Matrix object publicStringtoString() { Stringm = ""; for (intr = 0; r < numRows(); r++) { for (intc = 0; c < numCols(); c++) { m += matrix[r][c] + " "; } m += "\n"; } returnm; } // Get value at row r and column c publicdoublegetValue(intr, intc) { returnmatrix[r][c]; } // Set value at row r and column c publicvoidsetValue(intr, intc, doublevalue) { matrix[r][c] = value; } // Return product of this and other publicMatrixmultiply(Matrixother) { // TODO: complete method definition, replace this placeholder code Matrixproduct = newMatrix(0,0); returnproduct; } // main method to test Matrix class publicstaticvoidmain(String[] args) { Matrixa = newMatrix(2, 3); Matrixb = newMatrix(3, 2); a.fillMatrix(); b.fillMatrix(); Matrixproduct = a.multiply(b); System.out.println(a); System.out.println(b); System.out.println(product); } }

Matrix Multiplication Write a method called multiply in the Matrix class that takes an instance of Matrix as a parameter and returns the result of matrix multiplication. Complete the definition of the class Matrix and method definition multiply shown here and in the starter code. public class Matrix { public Matrix multiply(Matrix other) { // fill in code here } } For purposes of this exercise, you should assume (without checking) that the matrices to be multiplied have the correct shapes, ie, that this.numCols() is equivalent to other.numRows(). To multiply matrices, the number of columns in the first matrix must equal the number of rows in the second matrix. In general, if we multiply an m x n matrix A (ie, having m rows and n columns) by a n x p matrix B (ie, having n rows and p columns), the product will have size m x p (ie, m rows and p columns). Here is a simple illustration of the computation for two 2 x 2 matrices: Examples Example 1 If A and B were both instances of the Matrix class with the following data, respectively, 0.0 1.0 2.0 2.0 1.0 2.0 2.0 2.0 2.0 2.0 0.0 2.0 the product a.multiply(b) would be the Matrix containing the following data: 2.0 6.0 6.0 10.0 Example 2 If A and B were both instances of the Matrix class with the following data, respectively, 1.0 3.0 1.0 2.0 3.0 1.0 0.0 3.0 1.0 0.0 3.0 1.0 1.0 1.0 2.0 3.0 2.0 3.0 0.0 1.0 the product a.multiply(b) would be the Matrix containing the following data: 9.0 15.0 5.0 9.0 7.0 11.0 Matrix.java code is attached import java.util.Random; public class Matrix { // Largest random value in Matrix will be MAX_VALUE-1 privatestaticfinalintMAX_VALUE = 3; privatedouble[][] matrix; // Constructor initializes an empty matrix publicMatrix(intnumRows, intnumCols) { matrix = newdouble[numRows][numCols]; } // Fill Matrix with random small integers for testing publicvoidfillMatrix() { Randomrand = newRandom(); for (intr = 0; r < numRows(); r++) { for (intc = 0; c < numCols(); c++) { matrix[r][c] = rand.nextInt(MAX_VALUE); } } } // Return number of rows in Matrix object publicintnumRows() { returnmatrix.length; } // Return number of columns in Matrix object publicintnumCols() { return (matrix.length == 0) ?0:matrix[0].length; } // Return String representation of Matrix object publicStringtoString() { Stringm = ""; for (intr = 0; r < numRows(); r++) { for (intc = 0; c < numCols(); c++) { m += matrix[r][c] + " "; } m += "\n"; } returnm; } // Get value at row r and column c publicdoublegetValue(intr, intc) { returnmatrix[r][c]; } // Set value at row r and column c publicvoidsetValue(intr, intc, doublevalue) { matrix[r][c] = value; } // Return product of this and other publicMatrixmultiply(Matrixother) { // TODO: complete method definition, replace this placeholder code Matrixproduct = newMatrix(0,0); returnproduct; } // main method to test Matrix class publicstaticvoidmain(String[] args) { Matrixa = newMatrix(2, 3); Matrixb = newMatrix(3, 2); a.fillMatrix(); b.fillMatrix(); Matrixproduct = a.multiply(b); System.out.println(a); System.out.println(b); System.out.println(product); } }

Database System Concepts

7th Edition

ISBN:9780078022159

Author:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan

Publisher:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan

Chapter1: Introduction

Section: Chapter Questions

Problem 1PE

See similar textbooks

Matrix Multiplication

Write a method called multiply in the Matrix class that takes an instance of Matrix as a parameter and returns the result of matrix multiplication. Complete the definition of the class Matrix and method definition multiply shown here and in the starter code.

public class Matrix { public Matrix multiply(Matrix other) { // fill in code here } }

For purposes of this exercise, you should assume (without checking) that the matrices to be multiplied have the correct shapes, ie, that this.numCols() is equivalent to other.numRows().

To multiply matrices, the number of columns in the first matrix must equal the number of rows in the second matrix. In general, if we multiply an m x n matrix A (ie, having m rows and n columns) by a n x p matrix B (ie, having n rows and p columns), the product will have size m x p (ie, m rows and p columns).

Here is a simple illustration of the computation for two 2 x 2 matrices:

Examples

Example 1

If A and B were both instances of the Matrix class with the following data, respectively,

0.0 1.0 2.0 2.0 1.0 2.0 2.0 2.0 2.0 2.0 0.0 2.0

the product a.multiply(b) would be the Matrix containing the following data:

2.0 6.0 6.0 10.0

Example 2

If A and B were both instances of the Matrix class with the following data, respectively,

1.0 3.0 1.0 2.0 3.0 1.0 0.0 3.0 1.0 0.0 3.0 1.0 1.0 1.0 2.0 3.0 2.0 3.0 0.0 1.0

the product a.multiply(b) would be the Matrix containing the following data:

9.0 15.0 5.0 9.0 7.0 11.0

Matrix.java code is attached

import java.util.Random;

public class Matrix {

// Largest random value in Matrix will be MAX_VALUE-1

privatestaticfinalintMAX_VALUE = 3;

privatedouble[][] matrix;

// Constructor initializes an empty matrix

publicMatrix(intnumRows, intnumCols) {

matrix = newdouble[numRows][numCols];

}

// Fill Matrix with random small integers for testing

publicvoidfillMatrix() {

Randomrand = newRandom();

for (intr = 0; r < numRows(); r++) {

for (intc = 0; c < numCols(); c++) {

matrix[r][c] = rand.nextInt(MAX_VALUE);

}

// Return number of rows in Matrix object

publicintnumRows() {

returnmatrix.length;

}

// Return number of columns in Matrix object

publicintnumCols() {

return (matrix.length == 0) ?0:matrix[0].length;

}

// Return String representation of Matrix object

publicStringtoString() {

Stringm = "";

for (intr = 0; r < numRows(); r++) {

for (intc = 0; c < numCols(); c++) {

m += matrix[r][c] + " ";

}

m += "\n";

}

returnm;

}

// Get value at row r and column c

publicdoublegetValue(intr, intc) {

returnmatrix[r][c];

}

// Set value at row r and column c

publicvoidsetValue(intr, intc, doublevalue) {

matrix[r][c] = value;

}

// Return product of this and other

publicMatrixmultiply(Matrixother) {

// TODO: complete method definition, replace this placeholder code

Matrixproduct = newMatrix(0,0);

returnproduct;

}

// main method to test Matrix class

publicstaticvoidmain(String[] args) {

Matrixa = newMatrix(2, 3);

Matrixb = newMatrix(3, 2);

a.fillMatrix();

b.fillMatrix();

Matrixproduct = a.multiply(b);

System.out.println(a);

System.out.println(b);

System.out.println(product);

}

Expert Solution

Step by step

Solved in 4 steps with 4 images

SEE SOLUTION Check out a sample Q&A here

Knowledge Booster

Learn more about

Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, computer-science and related others by exploring similar questions and additional content below.