please i was trying to test a function that i have coded, but this message "subscripted assignment dimension mismatch" keeps appearing for every attempt. can someone help

function Y = trial_p(x,y)
    Y = 100*(x.^2-y)+(1-x).^2;
    end
    lb=[0 0];
    ub = [1 13];
    d=2;
    fobj = @trial_p
    function [bestfitness avefitness maxfitness minfitness] = PAD_SFA(fobj,lb,ub,d,para)
    %check input parameters 
    if nargin<5, para = [4 0.618 30 2.5 0.01 5];
        if nargin<4, d = 1;
            if nargin<3, ub=[];
                if nargin<2,lb =[];
                    if nargin<1, disp('globaloptim:PAD_SFA:InvalidInputStruct');
                        return
                    end
                end
            end
        end
    end
    %check if the confines are the same
    if length(lb)~=length(ub)
        disp('simple confines are improper');
        return
    end
    MaxGeneration = para(1); delta = para(2);
    n = para(3); visual= para(4);
    step = para(5); try_number = para(6);
    disp('/*=================================================================*/');
    disp('/*              Swarm Fish Optimistion                             */');                                   
    disp('/*=================================================================*/');
    disp('>>>>');
    disp('Begin to evaluate...waiting please...');
    home;
    tic;
    t = 0;
     sol = zeros(1,n);
        best = zeros(1,n);
    bestfitness = zeros(1,MaxGeneration);
    avefitness = zeros(1,MaxGeneration);
    maxfitness = zeros(1,MaxGeneration);
    minfitness = zeros(1,MaxGeneration);
    while (t<=MaxGeneration)
        for k = 1:n 
            sol(k,:) = lb + (ub-lb).*rand(1,d);
        end
        zn= zeros(1,n);
        for k = 1:n
            zn(k) = sol(k,:);
            neigh = zn(k) + visual.*rand;
            x1 = search_SFA(fobj,step,visual,zn,neigh,try_number);
            neigh = zn(k) + visual.*rand;
            x2 = swarm_SFA(fobj,step,visual,zn,neigh,delta,n);
            neigh = sol(k,d) + visual.*rand;
            x3 = follow_SFA(fobj,step,visual,zn,neigh,delta,n);
            yn = [x1 x2 x3];
            for i = 1:3
                yd = fhandle(yn(i));
            end
            [ybest ~] = sort(yd);
            best(k) = ybest(1);
        end
        t =t+1;
        [sfa ~] = sort(best);
        bestfitness = sfa(1);
        avefitness = mean(best);
        maxfitness = avefitness + std(best);
        minfitness = avefitness - std(best);
    end
    toc;
    disp('End Swarmfish evaluation');

          %---------------------------------------------------------------------
          %----------------------subfuctions------------------------------------
          %---------------------------------------------------------------------
          function [ts] = search_SFA(fhandle,step,visual,zn,neigh,try_number)
          if fhandle(neigh)<fhandle(sol)
              ts = zn + step.*rand.*((neigh-zn)/abs(neigh-zn));
          else
              for i = 1:try_number
                  neighk = zn + visual.*rand;
              end
                  %neighk(i) = zn;
                  for i = 1:5
                      if obj(neighk(i)) < obj(zn)
                          break
                      end
                      zy = zn + step.*rand.*((neigh-zn)/abs(neigh-zn));
                  end
                  if isempty(zy)
                      ts= zn + step.*randn;
                  end
          end

          function [th] = swarm_SFA(fhandle,step,visual,zn,neigh,delta,n)

                        df = fhandle(neigh); dg= fhandle(zn); dh =(visual/n);
                      if df < dg && dh < delta
                          th = zn + step.*rand.*((neigh-zn)/abs(neigh-zn));
                      else
                          th = search_SFA(fhandle,step,visual,zn,neigh,try_number);
                      end
              function [tz] = follow_SFA(fhandle,step,visual,zn,neigh,delta,n)
                       if fhandle(neigh) < fhandle(zn)&& ((visual/n) < delta)
                          tz = zn + step.*rand.*((neigh-zn)/abs(neigh-zn));
                      else
                          tz = search_SFA(fhandle,step,visual,zn,neigh);
                       end

[Star Strider]

What line throws the error?

What are the dimensions of the arrays you are referencing in it?

What are the subscript values you are referencing?

[Tijjani Aminu Kuda]

line 38 of the main function (sol(k,:) = lb + (ub-lb).*rand(1,d);) and the dimension of the arrays is 2 the main function is [ ] = PAD_SFA(fobj,lb,ub,d,para)

[Image Analyst]

Please, just give us the error message. Copy and paste ALL the red text - don't snip out just a portion of it.

[Tijjani Aminu Kuda]

Please find below the error message:

Subscripted assignment dimension mismatch.

Error in PAD_SFA (line 39) sol(k,:) = lb + (ub-lb).*rand(1,d);

Answer 1

[Guillaume]

I've not tried to understand your code, but sol is defined as a matrix with 1 row and n columns:

sol = zeros(1, n);

You then have a loop iterating from 1 to n, and use that iterator to index rows:

for k = 1:n
   sol(k, :) = ...

Remember, there's only one row, so for k > 1, your code won't work. I have no idea, if it should be

sol(1, k) = ...

in the loop, or if you should declare your sol as:

sol = zeros(n, n); %which can also be written as sol = zeros(n);

Answer 2

[Star Strider]

I didn’t run your code (I don’t know what the appropriate values of ‘x’ and ‘y’ should be), but there are a few obvious problems:

    if nargin<5, para = [4 0.618 30 2.5 0.01 5];
        if nargin<4, d = 1;
            if nargin<3, ub=[];
                if nargin<2,lb =[];
                    if nargin<1, disp('globaloptim:PAD_SFA:InvalidInputStruct');
                        return
                    end
                end
            end
        end
    end

You only have 2 input arguments, so ‘para’ (and therefore ‘n’), ‘d’, and ‘ub’ will never be defined. That means your ‘sol’ variable will likely not be defined as well.

What do you want to do?

Answer 3

[Image Analyst]

You have this:

sol = zeros(1, n);

meaning sol has n columns. But then you have this:

sol(k,:) = lb + (ub-lb).*rand(1,d);

and rand(1,d) is a 1-by-d row vector while sol(k,:) specifies n elements in the kth row. So does n equal d? If not, you'd get that message. For example it's not going to let you stuff a 20 element row vector into a row that is only 9 elements long - they MUST be the same size. I suggest you take a closer look at what n and d are and try to analyze what you're doing better.