simulated annealing code to minimize fitness function with 9 variables compare to genetic algorithm minimization in matlab

To implement a simulated annealing algorithm and a genetic algorithm in MATLAB to minimize a fitness function with 9 variables, you can follow the steps outlined below:

  1. Define your fitness function: Start by defining the fitness function that you want to minimize. This function should take the 9 variables as input and return a scalar value that represents the fitness of the solution.

  2. Simulated Annealing Algorithm:

    • Initialize the initial solution with random values for the 9 variables.
    • Set the initial temperature and cooling rate for the simulated annealing algorithm.
    • Repeat the following steps until the stopping criterion is met (e.g., the maximum number of iterations or a desired fitness value is reached):
      • Generate a new candidate solution by randomly perturbing the current solution.
      • Evaluate the fitness of the candidate solution.
      • Accept the candidate solution with a probability that depends on the difference between the fitness of the current and candidate solutions, as well as the current temperature.
      • Update the temperature according to the cooling rate.
    • Return the best solution found during the iterations.

    Here's an example of how this can be implemented in MATLAB:

    main.m
    % Define your fitness function
    fitnessFunc = @(x) yourFitnessFunction(x);
    
    % Initialize variables
    numVariables = 9;
    initialSolution = rand(1, numVariables);
    currentSolution = initialSolution;
    bestSolution = initialSolution;
    currentFitness = fitnessFunc(currentSolution);
    bestFitness = currentFitness;
    
    % Set parameters
    initialTemperature = 100;
    coolingRate = 0.9;
    maxIterations = 100;
    
    % Simulated Annealing Algorithm
    temperature = initialTemperature;
    for iteration = 1:maxIterations
        % Generate a new candidate solution
        candidateSolution = currentSolution + randn(1, numVariables);
        candidateFitness = fitnessFunc(candidateSolution);
    
        % Accept or reject the candidate solution
        if candidateFitness < currentFitness || rand() < exp((currentFitness - candidateFitness) / temperature)
            currentSolution = candidateSolution;
            currentFitness = candidateFitness;
        end
    
        % Update the best solution
        if candidateFitness < bestFitness
            bestSolution = candidateSolution;
            bestFitness = candidateFitness;
        end
    
        % Update the temperature
        temperature = temperature * coolingRate;
    end
    
    % Return the best solution found
    bestSolution
    
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  3. Genetic Algorithm:

    • Initialize the population with random values for the 9 variables.
    • Define the selection, crossover, and mutation operators for the genetic algorithm.
    • Repeat the following steps until the stopping criterion is met (e.g., the maximum number of generations or a desired fitness value is reached):
      • Evaluate the fitness of each individual in the population.
      • Select the parents for the next generation using the selection operator.
      • Create the offspring population by applying crossover and mutation operators to the selected parents.
      • Replace the current population with the offspring population.
    • Return the best solution found during the generations.

    Here's an example of how this can be implemented in MATLAB using the Global Optimization Toolbox:

    main.m
    % Define your fitness function
    fitnessFunc = @(x) yourFitnessFunction(x);
    
    % Set options for the genetic algorithm
    options = optimoptions('ga', 'PopulationSize', 100, 'MaxGenerations', 100, 'FunctionTolerance', 1e-6);
    
    % Run the genetic algorithm
    [bestSolution, bestFitness] = ga(fitnessFunc, 9, options);
    
    % Return the best solution found
    bestSolution
    
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    Note that in this example, the ga function from the Global Optimization Toolbox is used to run the genetic algorithm. You may need to adjust the options and other parameters based on your specific problem.

Remember to replace yourFitnessFunction with the actual implementation of your fitness function.

With both approaches, you may need to adjust the parameters and fine-tune the algorithms for your specific problem. Additionally, you can consider parallelizing the algorithms to speed up the execution using MATLAB's Parallel Computing Toolbox.

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