Concept explainers
(Sum elements column by column) Write a method that returns the sum of all the elements in a specified column in a matrix using the following header:
public static double sumColumn(double[][] m, int columnIndex)
Write a test
Sum of elements column by column
Program Plan:
- Include the “Scanner” package to get input values from user.
- Define the class named “Test”.
- Define the main method.
- Define the object “obj” for “Scanner” class to get input.
- Declare the multi-dimensional array named “array”, and prompt the user to get array input.
- Define the “for” loops, that get the input values for the variable “array”.
- Define the “for” loop, that call the method “sumColumn()” with two arguments, they are array and index of array.
- Define the method named “sumColumn()” with two arguments. One is a array variable “m” in type of “double” and another one is “columnIndex” with integer data type.
- Declare the variable “total” in type of “double” and initialize the variable with “0”.
- Set the “for” loop, the loop executes from “0” to length of array “m”.
- Add the column values and store it into the “total”.
- Return the value of “total”.
- Define the main method.
The following JAVA code is to sum the elements of array column by column using the method “sumColumn(double[][] m, int columnIndex)”.
Explanation of Solution
Program:
//Insert package
import java.util.Scanner;
//Class definition
public class Test
{
//Main method
public static void main(String[] args)
{
//Assign the object for "Scanner" class
Scanner obj = new Scanner(System.in);
//Print statement
System.out.print("Enter a 3 by 4 matrix row by row: ");
//Declaration of variable
double[][] array = new double[3][4];
//Outer loop
for (int i = 0; i < array.length; i++)
//Inner Loop
for (int j = 0; j <array[i].length; j++)
//Get input from user
array[i][j] = obj.nextDouble();
//Loop
for (int j = 0; j < array[0].length; j++)
{
//Print statement with function call
System.out.println("Sum of the elements at column " + j + " is " + sumColumn(array, j));
}
}
//Function definition
public static double sumColumn(double[][] m, int columnIndex)
{
//Declaration of variable
double total = 0;
//Loop
for (int i = 0; i < m.length; i++)
//Add the array values into variable
total += m[i][columnIndex];
//Return statement
return total;
}
}
Enter a 3 by 4 matrix row by row:
1.5 2 3 4
5.5 6 7 8
9.5 1 3 1
Sum of the elements at column 0 is 16.5
Sum of the elements at column 1 is 9.0
Sum of the elements at column 2 is 13.0
Sum of the elements at column 3 is 13.0
Want to see more full solutions like this?
Chapter 8 Solutions
Introduction to Java Programming and Data Structures, Comprehensive Version (11th Edition)
Additional Engineering Textbook Solutions
Starting Out with C++ from Control Structures to Objects (9th Edition)
Starting Out With Visual Basic (8th Edition)
Introduction To Programming Using Visual Basic (11th Edition)
Programming in C
Web Development and Design Foundations with HTML5 (9th Edition) (What's New in Computer Science)
Digital Fundamentals (11th Edition)
- i. Creates a matrix using: B=rand (20) a-write a program to find all numbers less than or equal 0.5 and put them in a new matrix with dimension 20x10. you can extend with zeros to fill the matrix. b- Do same as point a for all numbers above 0.5. c- Count all the numbers less or equal 0.3 , the numbers between 0.3 and 0.7 and count the numbers more than or equal 0.7.Put the results in a new vector with dimension 3x1. d- Replace the numbers of between 0.7 and 0.9 with 1. e- Add all the elements column wise.arrow_forwardCreate a program for Matrix with the following requirements: 1. Allow the user to select what operation to perform like: finding eigenvalues and eigenvectors, sketching the Gershgorin circles, and diagonalization. 2. Allow the user to input any size of the matrices and their elements. 3. Display the matrix input and the result of the operation.arrow_forward2-Write a test program that reads a 4-by-4 matrix and displays the multiply of each rowarrow_forward
- Write method body of following methods: DeleteNum(int position) // This method will delete element from array at position entered by the user arrange the data after that position to left. (Using While loop) DeleteNum(int from, int to) // This method will delete elements from array at range given by the user, as the user inputs two positions i.e start and end, the program should than delete all numbers in that range. (Use C++ to code)arrow_forwardAn array index should normally be of type float. State whether the statement is true or false. If false, explain why.arrow_forward(Two dice are rolled 100 times (you can do this with two random values from 1 to 6 in your program). After rounding 100 times, keep the iteration value of how many times each state occurs in a two-dimensional array. For example, the index number of [1,1] must follow the number of times the dice rolls 1 to 1).arrow_forward
- (FYI: Pseudocode is required (Not any programming language) Design a pseudocode program that loads an array with the following 7 values. Add one more word (of your own choosing) for a total of 8 words. biffcomelyfezmottleperukebedraggledquisling Be sure to use lowercase, as shown above. This will make the processing easier. Ask the user to enter a word Search through this array until you find a match with the word the user entered. Once you find a match, output "Yes, that word is in the dictionary". If you get to the end of the array and do NOT find a match, output "No, that word is not in the dictionary". The program should work with any set of words in the arrays. If I were to change the words in the arrays, it should still work. If you need help, look at the search example in your textbook.arrow_forwardIndicate true or false for the following statements: Every element in an array has the same type. The array size is fixed after it is declared. The array size declarator must be a constant expression. The array elements are initialized when an array is declared.arrow_forwardQ2: In this question, you will write a Python function to compute the Hadamard product of two matrices. The Hadamard product is the "component-wise" product of two matrices. That is, each entry of the product matrix is equal to the product of its corresponding entries of the input matrices. Here is an example: a11 a12 a21 a22 a23 a31 a13 SH a32 033 A b11 b12 b13 b21 b22 b23 b31 b32 b33. B = [an bu a21 b21 a31 b31 a12 b12 a22 b22 a32 b32 a13 b13 a23 b23 a33 b33. Hadamard product of A and B Write a Python function to compute the Hadamard product of two matrices as follows. a) The inputs to the function are two matrices. b) The function should check whether the two matrices have the same size. If not, it should print "The input matrices are not of the same size". c) If two matrices are of the same size, the function computes the Hadamard product and returns the answer. Use for loops to compute the Hadamard product.arrow_forward
- Write statements to do the following: i. Write a loop that computes the sum of all elements in the array, A ii. Write a loop that finds the minimum element in the array, A iii. Write a method to find the maximum in the array, Aarrow_forward(Compute total marks for each student) Suppose the marks obtained by all students are stored ina two-dimensional array. Each row records a student’s marks for five tests. For example, the followingarray stores the test marks for eight students. Write a program that displays students and the totalmarks they obtained in five tests, in decreasing order of the total marks.arrow_forwardcreate code, no if or return on it.arrow_forward
- Database System ConceptsComputer ScienceISBN:9780078022159Author:Abraham Silberschatz Professor, Henry F. Korth, S. SudarshanPublisher:McGraw-Hill EducationStarting Out with Python (4th Edition)Computer ScienceISBN:9780134444321Author:Tony GaddisPublisher:PEARSONDigital Fundamentals (11th Edition)Computer ScienceISBN:9780132737968Author:Thomas L. FloydPublisher:PEARSON
- C How to Program (8th Edition)Computer ScienceISBN:9780133976892Author:Paul J. Deitel, Harvey DeitelPublisher:PEARSONDatabase Systems: Design, Implementation, & Manag...Computer ScienceISBN:9781337627900Author:Carlos Coronel, Steven MorrisPublisher:Cengage LearningProgrammable Logic ControllersComputer ScienceISBN:9780073373843Author:Frank D. PetruzellaPublisher:McGraw-Hill Education