How to resolve the algorithm Element-wise operations step by step in the C# programming language

Published on 12 May 2024 09:40 PM
#C_Sharp

How to resolve the algorithm Element-wise operations step by step in the C# programming language

Table of Contents

Problem Statement

This task is similar to:

Implement basic element-wise matrix-matrix and scalar-matrix operations, which can be referred to in other, higher-order tasks. Implement:

Extend the task if necessary to include additional basic operations, which should not require their own specialised task.

Let's start with the solution:

Step by Step solution about How to resolve the algorithm Element-wise operations step by step in the C# programming language

The provided C# source code defines a static class ElementWiseOperations and a program class Program that demonstrates element-wise operations on 2D matrices. Here's a detailed explanation of the code:

  1. ElementWiseOperations Class:

    • Private Fields and Dictionaries:

      • operations is a private dictionary that maps operation names to delegate functions that perform element-wise operations. The supported operations are:
        • "add": addition
        • "sub": subtraction
        • "mul": multiplication
        • "div": division
        • "pow": exponentiation

    • DoOperation Methods:

      • There are two DoOperation methods that perform element-wise operations on 2D matrices.
        • The first DoOperation method takes three parameters: the source matrix m, the operation name name, and another matrix other. It performs the element-wise operation specified by the operation name on the two matrices and returns the result.
        • The second DoOperation method takes three parameters: the source matrix m, the operation delegate function operation, and another matrix other. It performs the element-wise operation specified by the delegate function on the two matrices and returns the result.

  2. Program Class:

    • Main Method:
      • Inside the Main method, a 3x4 matrix matrix and a 3x4 matrix tens are defined.
        • matrix is shown on the console.
        • Element-wise addition is performed on matrix and tens using the DoOperation method with the "add" operation name. The result is printed on the console.
        • Element-wise subtraction is performed on matrix with a constant value of 100 using the DoOperation method with a lambda expression. The result is printed on the console.

Example:

In the provided code, an example is given with a 3x4 matrix matrix and a 3x4 matrix tens. The element-wise addition of these two matrices is performed using the DoOperation method with the "add" operation name. The result is a new 3x4 matrix where each element is the sum of the corresponding elements in matrix and tens.

Similarly, an element-wise subtraction is performed on matrix with a constant value of 100 using a lambda expression delegate. The result is a new 3x4 matrix where each element is the difference between the corresponding element in matrix and the constant value 100.

The output of the example would be:

[ 1, 2, 3, 4 ]
[ 5, 6, 7, 8 ]
[ 9, 10, 11, 12 ]


[ 11, 12, 13, 14 ]
[ 25, 26, 27, 28 ]
[ 39, 40, 41, 42 ]


[ -99, -98, -97, -96 ]
[ -95, -94, -93, -92 ]
[ -91, -90, -89, -88 ]

Source code in the csharp programming language

using System;
using System.Collections.Generic;
using System.Linq;

public static class ElementWiseOperations
{
    private static readonly Dictionary<string, Func<double, double, double>> operations =
        new Dictionary<string, Func<double, double, double>> {
            { "add", (a, b) => a + b },
            { "sub", (a, b) => a - b },
            { "mul", (a, b) => a * b },
            { "div", (a, b) => a / b },
            { "pow", (a, b) => Math.Pow(a, b) }
        };

    private static readonly Func<double, double, double> nothing = (a, b) => a;

    public static double[,] DoOperation(this double[,] m, string name, double[,] other) =>
        DoOperation(m, operations.TryGetValue(name, out var operation) ? operation : nothing, other);

    public static double[,] DoOperation(this double[,] m, Func<double, double, double> operation, double[,] other) {
        if (m == null || other == null) throw new ArgumentNullException();
        int rows = m.GetLength(0), columns = m.GetLength(1);
        if (rows != other.GetLength(0) || columns != other.GetLength(1)) {
            throw new ArgumentException("Matrices have different dimensions.");
        }

        double[,] result = new double[rows, columns];
        for (int r = 0; r < rows; r++) {
            for (int c = 0; c < columns; c++) {
                result[r, c] = operation(m[r, c], other[r, c]);
            }
        }
        return result;
    }

    public static double[,] DoOperation(this double[,] m, string name, double number) =>
        DoOperation(m, operations.TryGetValue(name, out var operation) ? operation : nothing, number);

    public static double[,] DoOperation(this double[,] m, Func<double, double, double> operation, double number) {
        if (m == null) throw new ArgumentNullException();
        int rows = m.GetLength(0), columns = m.GetLength(1);
        double[,] result = new double[rows, columns];
        for (int r = 0; r < rows; r++) {
            for (int c = 0; c < columns; c++) {
                result[r, c] = operation(m[r, c], number);
            }
        }
        return result;
    }

    public static void Print(this double[,] m) {
        if (m == null) throw new ArgumentNullException();
        int rows = m.GetLength(0), columns = m.GetLength(1);
        for (int r = 0; r < rows; r++) {
            Console.WriteLine("[ " + string.Join(", ", Enumerable.Range(0, columns).Select(c => m[r, c])) + " ]");
        }
    }

}

public class Program
{
    public static void Main() {
        double[,] matrix = {
            { 1, 2, 3, 4 },
            { 5, 6, 7, 8 },
            { 9, 10, 11, 12 }
        };

        double[,] tens = {
            { 10, 10, 10, 10 },
            { 20, 20, 20, 20 },
            { 30, 30, 30, 30 }
        };

        matrix.Print();
        WriteLine();

        (matrix = matrix.DoOperation("add", tens)).Print();
        WriteLine();

        matrix.DoOperation((a, b) => b - a, 100).Print();
    }
}

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