MATLAB: For loop not stopping

for loop

Why is my for loop not stopping? I have tried both break and end and thought it would end if I added an increment but it does not.

string = "HOWDY";
count = 0;
for count = 1:strlength(string)
        count = count + 1
    end

Best Answer

string = "HOWDY";
c = 0;
for count = 1:strlength(string)
        c = c + 1;%should never mess with the loop variable inside the loop
end

Related Solutions

MATLAB: Stopping criterion in GA

alexaa - what you can do is compare, at each generation, the best found solution with the best one from the previous generation/iteration. If the absolute difference between the two is less than some tolerance, then they can be considered equal, and you just increment a counter. When that counter hits 100, exit the loop (I'm guessing that you will be using a for or while loop).

Try the following

 % initialize a local variable to keep track of the previous generation's best fitness
 prevGenBestFitness     = [];
 % initialize our counter
 numGensWithSameFitness = 0;
 % define a tolerance (note that this assumes real fitness scores, if
 % your fitness scores are integer, then this should be set to one or 
 % something similar)
 tol = 0.00001;
 % do the GA; this will be your for or while loop
 while true
     % do the GA stuff
     % save the best fitness from the current generation
     bestFitness = …;
     % compare this best with the previous best (we use ~empty to capture
     % the first iteration when there is nothing to compare)
     if ~isempty(prevGenBestFitness)
         % we can compare
         % NOTE I'm assuming that the best fitness from the current generation is
         % always as good or better than the fitness from the previous generation
         if abs(prevGenBestFitness-bestFitness)<tol
             % the two fitnesses are considered identical so increment the
             % counter
             numGensWithSameFitness = numGensWithSameFitness + 1;
             if numGensWithSameFitness==100
                 % 100 generations with same fitness, so exit
                 break;
             end
         else
             % the two fitnesses are not identical so reset the counter
             numGensWithSameFitness = 0;
         end
     end
     prevGenBestFitness = bestFitness;
 end

Note that the above does make certain assumptions about the fitness/score for your population and so may have to be adjusted to take into account a different scoring scheme (or data type).

Try the above and see what happens!

Best Answer

Related Solutions

MATLAB: Stopping criterion in GA

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